diff --git a/source/copytable.pas b/source/copytable.pas
index 7494d818..e069c208 100644
--- a/source/copytable.pas
+++ b/source/copytable.pas
@@ -279,44 +279,48 @@ begin
   if radioStructure.Checked then
     strquery := strquery + ' WHERE 1 = 0';
 
-  Mainform.Connection.Query(strquery, False);
+  try
+    Mainform.Connection.Query(strquery, False);
 
-  // Fix missing auto_increment property and CURRENT_TIMESTAMP defaults in new table
-  Results := Mainform.Connection.GetResults('SHOW FIELDS FROM ' + mainform.mask(oldtablename));
-  Fixes := TWideStringlist.Create;
-  while not Results.Eof do begin
-    notnull := '';
-    if Results.Col('Null') = '' then
-      notnull := 'NOT NULL';
-    default := '';
-    if Results.Col('Default') <> '' then begin
-      default := 'DEFAULT ';
-      if Results.Col('Default') = 'CURRENT_TIMESTAMP' then
-        default := default + Results.Col('Default')
-      else
-        default := default + esc(Results.Col('Default'));
+    // Fix missing auto_increment property and CURRENT_TIMESTAMP defaults in new table
+    Results := Mainform.Connection.GetResults('SHOW FIELDS FROM ' + mainform.mask(oldtablename));
+    Fixes := TWideStringlist.Create;
+    while not Results.Eof do begin
+      notnull := '';
+      if Results.Col('Null') = '' then
+        notnull := 'NOT NULL';
+      default := '';
+      if Results.Col('Default') <> '' then begin
+        default := 'DEFAULT ';
+        if Results.Col('Default') = 'CURRENT_TIMESTAMP' then
+          default := default + Results.Col('Default')
+        else
+          default := default + esc(Results.Col('Default'));
+      end;
+
+      if (CheckBoxWithIndexes.Checked and (Results.Col('Extra') = 'auto_increment'))
+        or (Results.Col('Default') = 'CURRENT_TIMESTAMP') then begin
+        Fixes.Add('CHANGE '+Mainform.mask(Results.Col('Field'))+' '+
+          Mainform.mask(Results.Col('Field'))+' '+
+          Results.Col('Type')+' '+default+' '+notnull+' '+Results.Col('Extra'));
+      end;
+
+      Results.Next;
     end;
-
-    if (CheckBoxWithIndexes.Checked and (Results.Col('Extra') = 'auto_increment'))
-      or (Results.Col('Default') = 'CURRENT_TIMESTAMP') then begin
-      Fixes.Add('CHANGE '+Mainform.mask(Results.Col('Field'))+' '+
-        Mainform.mask(Results.Col('Field'))+' '+
-        Results.Col('Type')+' '+default+' '+notnull+' '+Results.Col('Extra'));
+    if Fixes.Count > 0 then begin
+      Mainform.Connection.Query('ALTER TABLE '+Mainform.mask(ComboSelectDatabase.Text) + '.'+Mainform.mask(editNewTablename.Text)+ ' '+
+        ImplodeStr(', ', Fixes)
+        );
+    end;
+    Results.Free;
+    FreeAndNil(Fixes);
+    Mainform.actRefresh.Execute;
+  except
+    on E:Exception do begin
+      MessageDlg(E.Message, mtError, [mbOk], 0);
+      ModalResult := mrNone;
     end;
-
-    Results.Next;
   end;
-  if Fixes.Count > 0 then begin
-    Mainform.Connection.Query('ALTER TABLE '+Mainform.mask(ComboSelectDatabase.Text) + '.'+Mainform.mask(editNewTablename.Text)+ ' '+
-      ImplodeStr(', ', Fixes)
-      );
-  end;
-  Results.Free;
-  FreeAndNil(Fixes);
-
-  Mainform.actRefresh.Execute;
-  close;
-
 end;
 
 procedure TCopyTableForm.CheckListBoxFieldsClickCheck(Sender: TObject);
diff --git a/source/editvar.pas b/source/editvar.pas
index 327cd3fe..3002537c 100644
--- a/source/editvar.pas
+++ b/source/editvar.pas
@@ -72,8 +72,10 @@ begin
   try
     Mainform.Connection.Query(sql);
   except
-    ModalResult := mrNone;
-    Raise;
+    on E:Exception do begin
+      ModalResult := mrNone;
+      MessageDlg(E.Message, mtError, [mbOK], 0);
+    end;
   end;
 end;
 
diff --git a/source/loaddata.pas b/source/loaddata.pas
index 40aeebe6..e70749e5 100644
--- a/source/loaddata.pas
+++ b/source/loaddata.pas
@@ -290,8 +290,14 @@ begin
 //  if col.Count < ColumnsCheckListBox.Items.Count then
   query := query + '(' + implodestr(',', col) + ')';
 
-  Mainform.Connection.Query(query);
-  close;
+  try
+    Mainform.Connection.Query(query);
+  except
+    on E:Exception do begin
+      MessageDlg(E.Message, mtError, [mbOk], 0);
+      ModalResult := mrNone;
+    end;
+  end;
 end;
 
 procedure Tloaddataform.btnOpenFileClick(Sender: TObject);
diff --git a/source/main.pas b/source/main.pas
index b19c54cc..5eef8257 100644
--- a/source/main.pas
+++ b/source/main.pas
@@ -1009,15 +1009,20 @@ var
 begin
   flushwhat := UpperCase(TAction(Sender).Caption);
   delete(flushwhat, pos('&', flushwhat), 1);
-  Connection.Query('FLUSH ' + flushwhat);
-  if Sender = actFlushTableswithreadlock then begin
-    MessageDlg(
-      'Tables have been flushed and read lock acquired.'#10 +
-      'Perform backup or snapshot of table data files now.'#10 +
-      'Press OK to unlock when done...',
-      mtInformation, [mbOk], 0
-    );
-    Connection.Query('UNLOCK TABLES');
+  try
+    Connection.Query('FLUSH ' + flushwhat);
+    if Sender = actFlushTableswithreadlock then begin
+      MessageDlg(
+        'Tables have been flushed and read lock acquired.'#10 +
+        'Perform backup or snapshot of table data files now.'#10 +
+        'Press OK to unlock when done...',
+        mtInformation, [mbOk], 0
+      );
+      Connection.Query('UNLOCK TABLES');
+    end;
+  except
+    on E:Exception do
+      MessageDlg(E.Message, mtError, [mbOK], 0);
   end;
 end;
 
@@ -2221,15 +2226,15 @@ begin
       lntDb: begin
         if MessageDlg('Drop Database "'+activeDB+'"?' + crlf + crlf + 'WARNING: You will lose all tables in database '+activeDB+'!', mtConfirmation, [mbok,mbcancel], 0) <> mrok then
           Abort;
-        Screen.Cursor := crHourglass;
         try
           Connection.Query('DROP DATABASE ' + mask(activeDB));
-        finally
           DBtree.FocusedNode := DBtree.GetFirst;
           DBTree.Selected[DBtree.FocusedNode] := True;
           ClearDbTableList(activeDB);
           RefreshTree(False);
-          Screen.Cursor := crDefault;
+        except
+          on E:Exception do
+            MessageDlg(E.Message, mtError, [mbOK], 0);
         end;
         Exit;
       end;
@@ -2266,14 +2271,18 @@ begin
   if MessageDlg(msg, mtConfirmation, [mbok,mbcancel], 0) <> mrok then
     Exit;
 
-  // Compose and run DROP [TABLE|VIEW|...] queries
-  DoDrop('TABLE', Tables, True);
-  DoDrop('VIEW', Views, True);
-  DoDrop('PROCEDURE', Procedures, False);
-  DoDrop('FUNCTION', Functions, False);
-
-  // Refresh ListTables + dbtree so the dropped tables are gone:
-  actRefresh.Execute;
+  try
+    // Compose and run DROP [TABLE|VIEW|...] queries
+    DoDrop('TABLE', Tables, True);
+    DoDrop('VIEW', Views, True);
+    DoDrop('PROCEDURE', Procedures, False);
+    DoDrop('FUNCTION', Functions, False);
+    // Refresh ListTables + dbtree so the dropped tables are gone:
+    actRefresh.Execute;
+  except
+    on E:Exception do
+      MessageDlg(E.Message, mtError, [mbOK], 0);
+  end;
 end;
 
 
@@ -2481,10 +2490,15 @@ begin
   else
     sql_pattern := 'TRUNCATE ';
 
-  for i:=0 to t.count-1 do
-    Connection.Query( sql_pattern + mask(t[i]) );
+  try
+    for i:=0 to t.count-1 do
+      Connection.Query( sql_pattern + mask(t[i]) );
+    actRefresh.Execute;
+  except
+    on E:Exception do
+      MessageDlg(E.Message, mtError, [mbOK], 0);
+  end;
   t.Free;
-  actRefresh.Execute;
   Screen.Cursor := crDefault;
 end;
 
@@ -3902,13 +3916,17 @@ begin
   ProcessIDs := GetVTCaptions( ListProcesses, True );
   if MessageDlg('Kill '+inttostr(ProcessIDs.count)+' Process(es)?', mtConfirmation, [mbok,mbcancel], 0) = mrok then
   begin
-    for i := 0 to ProcessIDs.Count - 1 do
-    begin
-      // Don't kill own process
-      if ProcessIDs[i] = IntToStr(Connection.ThreadId) then
-        LogSQL('Ignoring own process id '+ProcessIDs[i]+' when trying to kill it.')
-      else
-        Connection.Query('KILL '+ProcessIDs[i]);
+    try
+      for i:=0 to ProcessIDs.Count-1 do begin
+        // Don't kill own process
+        if ProcessIDs[i] = IntToStr(Connection.ThreadId) then
+          LogSQL('Ignoring own process id '+ProcessIDs[i]+' when trying to kill it.')
+        else
+          Connection.Query('KILL '+ProcessIDs[i]);
+      end;
+    except
+      on E:Exception do
+        MessageDlg(E.Message, mtError, [mbOK], 0);
     end;
     ListProcesses.Tag := VTREE_NOTLOADED;
     ListProcesses.Repaint;
@@ -4354,10 +4372,8 @@ begin
     RefreshActiveDbTableList;
     DBTree.InvalidateChildren(FindDBNode(ActiveDatabase), True);
   except
-    On E : Exception do
-    begin
-      MessageDlg( E.Message, mtError, [mbOK], 0 );
-    end;
+    on E:Exception do
+      MessageDlg(E.Message, mtError, [mbOK], 0);
   end;
 end;
 
diff --git a/source/routine_editor.pas b/source/routine_editor.pas
index 6f6201ce..203d3d36 100644
--- a/source/routine_editor.pas
+++ b/source/routine_editor.pas
@@ -439,46 +439,51 @@ begin
   // There is no way to ALTER parameters or the name of it.
   // Create a temp routine, check for syntax errors, then drop the old routine and create it.
   // See also: http://dev.mysql.com/doc/refman/5.0/en/alter-procedure.html
-  if FAlterRoutineName <> '' then begin
-    // Create temp name
-    i := 0;
-    allRoutineNames := Mainform.Connection.GetCol('SELECT ROUTINE_NAME FROM '+Mainform.mask(DBNAME_INFORMATION_SCHEMA)+'.'+Mainform.mask('ROUTINES')+
-      ' WHERE ROUTINE_SCHEMA = '+esc(Mainform.ActiveDatabase)+
-      ' AND ROUTINE_TYPE = '+esc(ProcOrFunc)
-      );
-    TargetExists := ((editName.Text <> FAlterRoutineName) or (ProcOrFunc <> FAlterRoutineType)) and
-      (allRoutineNames.IndexOf(editName.Text) > -1);
-    if TargetExists then begin
-      if MessageDlg('Routine "'+editName.Text+'" already exists. Overwrite it?',
-        mtConfirmation, [mbOk, mbCancel], 0) = mrCancel then begin
-        Exit;
+  try
+    if FAlterRoutineName <> '' then begin
+      // Create temp name
+      i := 0;
+      allRoutineNames := Mainform.Connection.GetCol('SELECT ROUTINE_NAME FROM '+Mainform.mask(DBNAME_INFORMATION_SCHEMA)+'.'+Mainform.mask('ROUTINES')+
+        ' WHERE ROUTINE_SCHEMA = '+esc(Mainform.ActiveDatabase)+
+        ' AND ROUTINE_TYPE = '+esc(ProcOrFunc)
+        );
+      TargetExists := ((editName.Text <> FAlterRoutineName) or (ProcOrFunc <> FAlterRoutineType)) and
+        (allRoutineNames.IndexOf(editName.Text) > -1);
+      if TargetExists then begin
+        if MessageDlg('Routine "'+editName.Text+'" already exists. Overwrite it?',
+          mtConfirmation, [mbOk, mbCancel], 0) = mrCancel then begin
+          Exit;
+        end;
+      end;
+      while True do begin
+        inc(i);
+        TempName := APPNAME + '_temproutine_' + IntToStr(i);
+        if allRoutineNames.IndexOf(TempName) = -1 then
+          break;
+      end;
+      TempSQL := 'CREATE '+ProcOrFunc+' '+Mainform.mask(tempName)+'(' + BaseSQL;
+      Mainform.Connection.Query(TempSQL);
+      // Drop temporary routine, used for syntax checking
+      Mainform.Connection.Query('DROP '+ProcOrFunc+' IF EXISTS '+Mainform.mask(TempName));
+      // Drop edited routine
+      Mainform.Connection.Query('DROP '+FAlterRoutineType+' IF EXISTS '+Mainform.mask(FAlterRoutineName));
+      if TargetExists then begin
+        // Drop target routine - overwriting has been confirmed, see above
+        Mainform.Connection.Query('DROP '+ProcOrFunc+' IF EXISTS '+Mainform.mask(editName.Text));
       end;
     end;
-    while True do begin
-      inc(i);
-      TempName := APPNAME + '_temproutine_' + IntToStr(i);
-      if allRoutineNames.IndexOf(TempName) = -1 then
-        break;
-    end;
-    TempSQL := 'CREATE '+ProcOrFunc+' '+Mainform.mask(tempName)+'(' + BaseSQL;
-    Mainform.Connection.Query(TempSQL);
-    // Drop temporary routine, used for syntax checking
-    Mainform.Connection.Query('DROP '+ProcOrFunc+' IF EXISTS '+Mainform.mask(TempName));
-    // Drop edited routine
-    Mainform.Connection.Query('DROP '+FAlterRoutineType+' IF EXISTS '+Mainform.mask(FAlterRoutineName));
-    if TargetExists then begin
-      // Drop target routine - overwriting has been confirmed, see above
-      Mainform.Connection.Query('DROP '+ProcOrFunc+' IF EXISTS '+Mainform.mask(editName.Text));
-    end;
+    FinalSQL := 'CREATE '+ProcOrFunc+' '+Mainform.mask(editName.Text)+'(' + BaseSQL;
+    Mainform.Connection.Query(FinalSQL);
+    // Set editing name if create/alter query was successful
+    FAlterRoutineName := editName.Text;
+    FAlterRoutineType := ProcOrFunc;
+    Mainform.SetEditorTabCaption(Self, FAlterRoutineName);
+    Mainform.actRefresh.Execute;
+    Modified := False;
+  except
+    on E:Exception do
+      MessageDlg(E.Message, mtError, [mbOk], 0);
   end;
-  FinalSQL := 'CREATE '+ProcOrFunc+' '+Mainform.mask(editName.Text)+'(' + BaseSQL;
-  Mainform.Connection.Query(FinalSQL);
-  // Set editing name if create/alter query was successful
-  FAlterRoutineName := editName.Text;
-  FAlterRoutineType := ProcOrFunc;
-  Mainform.SetEditorTabCaption(Self, FAlterRoutineName);
-  Mainform.actRefresh.Execute;
-  Modified := False;
 end;
 
 
diff --git a/source/table_editor.pas b/source/table_editor.pas
index 69d2dcd2..33e5dfc8 100644
--- a/source/table_editor.pas
+++ b/source/table_editor.pas
@@ -560,46 +560,51 @@ var
   FocusChangeEvent: procedure(Sender: TBaseVirtualTree; Node: PVirtualNode; Column: TColumnIndex) of object;
 begin
   // Create or alter table
-  if FAlterTableName = '' then
-    sql := ComposeCreateStatement
-  else begin
-    sql := ComposeAlterStatement;
-    // Special case for altered foreign keys: These have to be dropped in a seperate query
-    // otherwise the server would return error 121 "Duplicate key on write or update"
-    // See also http://dev.mysql.com/doc/refman/5.1/en/innodb-foreign-key-constraints.html :
-    //   "You cannot add a foreign key and drop a foreign key in separate clauses of a single
-    //   ALTER TABLE  statement. Separate statements are required."
-    Specs := TWideStringList.Create;
-    for i:=0 to ForeignKeys.Count-1 do begin
-      Key := ForeignKeys[i] as TForeignKey;
-      if Key.Modified and (not Key.Added) then
-        Specs.Add('DROP FOREIGN KEY '+Mainform.mask(Key.KeyName));
+  try
+    if FAlterTableName = '' then
+      sql := ComposeCreateStatement
+    else begin
+      sql := ComposeAlterStatement;
+      // Special case for altered foreign keys: These have to be dropped in a seperate query
+      // otherwise the server would return error 121 "Duplicate key on write or update"
+      // See also http://dev.mysql.com/doc/refman/5.1/en/innodb-foreign-key-constraints.html :
+      //   "You cannot add a foreign key and drop a foreign key in separate clauses of a single
+      //   ALTER TABLE  statement. Separate statements are required."
+      Specs := TWideStringList.Create;
+      for i:=0 to ForeignKeys.Count-1 do begin
+        Key := ForeignKeys[i] as TForeignKey;
+        if Key.Modified and (not Key.Added) then
+          Specs.Add('DROP FOREIGN KEY '+Mainform.mask(Key.KeyName));
+      end;
+      if Specs.Count > 0 then
+        Mainform.Connection.Query('ALTER TABLE '+Mainform.mask(FAlterTableName)+' '+ImplodeStr(', ', Specs));
     end;
-    if Specs.Count > 0 then
-      Mainform.Connection.Query('ALTER TABLE '+Mainform.mask(FAlterTableName)+' '+ImplodeStr(', ', Specs));
-  end;
-  Mainform.Connection.Query(sql);
-  // Set table name for altering if Apply was clicked
-  FAlterTableName := editName.Text;
-  tabALTERcode.TabVisible := FAlterTableName <> '';
-  if chkCharsetConvert.Checked then begin
-    // Autoadjust column collations
-    for i:=0 to FColumns.Count-1 do begin
-      Col := FColumns[i] as TColumn;
-      if Col.Collation <> '' then
-        Col.Collation := comboCollation.Text;
+    Mainform.Connection.Query(sql);
+    // Set table name for altering if Apply was clicked
+    FAlterTableName := editName.Text;
+    tabALTERcode.TabVisible := FAlterTableName <> '';
+    if chkCharsetConvert.Checked then begin
+      // Autoadjust column collations
+      for i:=0 to FColumns.Count-1 do begin
+        Col := FColumns[i] as TColumn;
+        if Col.Collation <> '' then
+          Col.Collation := comboCollation.Text;
+      end;
     end;
-  end;
-  ResetModificationFlags;
+    ResetModificationFlags;
 
-  // Refresh db tree and reselect edited table node.
-  // Supress tab jumping, implicitely invoked by RefreshTreeDB.
-  FocusChangeEvent := Mainform.DBtree.OnFocusChanged;
-  Mainform.DBtree.OnFocusChanged := nil;
-  Mainform.RefreshTreeDB(Mainform.ActiveDatabase);
-  Mainform.DBtree.OnFocusChanged := FocusChangeEvent;
-  Mainform.ResetSelectedTableStuff;
-  Mainform.SelectDBObject(FAlterTableName, lntTable);
+    // Refresh db tree and reselect edited table node.
+    // Supress tab jumping, implicitely invoked by RefreshTreeDB.
+    FocusChangeEvent := Mainform.DBtree.OnFocusChanged;
+    Mainform.DBtree.OnFocusChanged := nil;
+    Mainform.RefreshTreeDB(Mainform.ActiveDatabase);
+    Mainform.DBtree.OnFocusChanged := FocusChangeEvent;
+    Mainform.ResetSelectedTableStuff;
+    Mainform.SelectDBObject(FAlterTableName, lntTable);
+  except
+    on E:Exception do
+      MessageDlg(E.Message, mtError, [mbOk], 0);
+  end;
 end;
 
 
diff --git a/source/usermanager.dfm b/source/usermanager.dfm
index cd3e1ad0..26eb8068 100644
--- a/source/usermanager.dfm
+++ b/source/usermanager.dfm
@@ -71,7 +71,6 @@ object UserManagerForm: TUserManagerForm
     Anchors = [akRight, akBottom]
     Caption = 'OK'
     Default = True
-    ModalResult = 1
     TabOrder = 2
     OnClick = btnOKClick
   end
diff --git a/source/usermanager.pas b/source/usermanager.pas
index a0f3d8e3..fbdec55c 100644
--- a/source/usermanager.pas
+++ b/source/usermanager.pas
@@ -296,7 +296,17 @@ begin
   lblHostHints.Caption := StringReplace(lblHostHints.Caption, '$SNR', snr, []);
 
   // Load users into memory
-  Users := TUsers.Create;
+  try
+    Users := TUsers.Create;
+  except
+    // At least one priv table is missing or non-accessible when we get an exception.
+    // Proceeding would result in follow up errors, so cancel the whole dialog in that case.
+    on E:Exception do begin
+      MessageDlg(E.Message+CRLF+CRLF+'The user manager cannot proceed with this error.', mtError, [mbOK], 0);
+      PostMessage(Handle, WM_CLOSE, 0, 0); 
+      Exit;
+    end;
+  end;
   // Enable limitations editors only if relevant columns exist
   lblMaxQuestions.Enabled := dsUser.ColExists('max_questions');
   editMaxQuestions.Enabled := lblMaxQuestions.Enabled;
@@ -885,11 +895,6 @@ var
   begin
     Mainform.LogSQL(sql);
   end;
-  procedure Exec(sql: String);
-  begin
-    //LogSQL(sql);  Exit;
-    Mainform.Connection.Query(sql);
-  end;
   function Mask(sql: String): String;
   begin
     Result := Mainform.Mask(sql);
@@ -929,10 +934,17 @@ begin
     LogSQL('Deleting account ' + u.FOldName + '@' + u.FOldHost + '.');
     AcctWhere := AccountSqlClause(u.FOldName, u.FOldHost, True);
     sql := 'DELETE FROM ' + db + '.';
-    Exec(sql + mask(PRIVTABLE_COLUMNS) + AcctWhere);
-    Exec(sql + mask(PRIVTABLE_TABLES) + AcctWhere);
-    Exec(sql + mask(PRIVTABLE_DB) + AcctWhere);
-    Exec(sql + mask(PRIVTABLE_USERS) + AcctWhere);
+    try
+      Mainform.Connection.Query(sql + mask(PRIVTABLE_COLUMNS) + AcctWhere);
+      Mainform.Connection.Query(sql + mask(PRIVTABLE_TABLES) + AcctWhere);
+      Mainform.Connection.Query(sql + mask(PRIVTABLE_DB) + AcctWhere);
+      Mainform.Connection.Query(sql + mask(PRIVTABLE_USERS) + AcctWhere);
+    except
+      on E:Exception do begin
+        MessageDlg(E.Message, mtError, [mbOK], 0);
+        Exit;
+      end;
+    end;
   end;
 
   AcctUpdates := TWideStringList.Create;
@@ -958,11 +970,18 @@ begin
     AcctWhere := AccountSqlClause(u.FOldName, u.FOldHost);
     AcctValues := ' SET ' + Delim(AcctUpdates);
     sql := 'UPDATE ' + db + '.';
-    // Todo: Allow concurrency by skipping this account and removing from Users array if changing key in mysql.user fails.
-    Exec(sql + mask(PRIVTABLE_USERS) + AcctValues + AcctWhere);
-    Exec(sql + mask(PRIVTABLE_DB) + AcctValues + AcctWhere);
-    Exec(sql + mask(PRIVTABLE_TABLES) + AcctValues + AcctWhere);
-    Exec(sql + mask(PRIVTABLE_COLUMNS) + AcctValues + AcctWhere);
+    try
+      // Todo: Allow concurrency by skipping this account and removing from Users array if changing key in mysql.user fails.
+      Mainform.Connection.Query(sql + mask(PRIVTABLE_USERS) + AcctValues + AcctWhere);
+      Mainform.Connection.Query(sql + mask(PRIVTABLE_DB) + AcctValues + AcctWhere);
+      Mainform.Connection.Query(sql + mask(PRIVTABLE_TABLES) + AcctValues + AcctWhere);
+      Mainform.Connection.Query(sql + mask(PRIVTABLE_COLUMNS) + AcctValues + AcctWhere);
+    except
+      on E:Exception do begin
+        MessageDlg(E.Message, mtError, [mbOK], 0);
+        Exit;
+      end;
+    end;
   end;
 
   LogSQL('Applying changes to authentication details and limitations...');
@@ -1000,7 +1019,14 @@ begin
     AcctWhere := AccountSqlClause(u.Name, u.Host);
     AcctValues := ' SET ' + Delim(AcctUpdates);
     sql := 'UPDATE ' + db + '.';
-    Exec(sql + mask(PRIVTABLE_USERS) + AcctValues + AcctWhere);
+    try
+      Mainform.Connection.Query(sql + mask(PRIVTABLE_USERS) + AcctValues + AcctWhere);
+    except
+      on E:Exception do begin
+        MessageDlg(E.Message, mtError, [mbOK], 0);
+        Exit;
+      end;
+    end;
   end;
 
   LogSQL('Creating new accounts...');
@@ -1037,8 +1063,15 @@ begin
       AcctUpdates.Add(mask('x509_subject') + '=' + esc(''));
     sql := 'INSERT INTO ' + db + '.' + mask(PRIVTABLE_USERS);
     sql := sql + ' SET ' + Delim(AcctUpdates);
-    // Todo: Allow concurrency by skipping this account and removing from Users array if inserting key in mysql.user fails.
-    Exec(sql);
+    try
+      // Todo: Allow concurrency by skipping this account and removing from Users array if inserting key in mysql.user fails.
+      Mainform.Connection.Query(sql);
+    except
+      on E:Exception do begin
+        MessageDlg(E.Message, mtError, [mbOK], 0);
+        Exit;
+      end;
+    end;
   end;
 
   LogSQL('Applying privilege changes...');
@@ -1100,12 +1133,26 @@ begin
         end;
         sql := 'UPDATE ' + db + '.' + mask(PRIVTABLE_USERS);
         sql := sql + ' SET ' + Delim(PrivUpdates);
-        Exec(sql + AcctWhere);
+        try
+          Mainform.Connection.Query(sql + AcctWhere);
+        except
+          on E:Exception do begin
+            MessageDlg(E.Message, mtError, [mbOK], 0);
+            Exit;
+          end;
+        end;
       end;
       // Remove old privilege definition.
       if (p.DBOType <> lntNone) then begin
         sql := 'DELETE FROM ' + db + '.' + TableName;
-        Exec(sql + AcctWhere + PrivWhere);
+        try
+          Mainform.Connection.Query(sql + AcctWhere + PrivWhere);
+        except
+          on E:Exception do begin
+            MessageDlg(E.Message, mtError, [mbOK], 0);
+            Exit;
+          end;
+        end;
       end else begin
         // Special case: avoid removing old definition when dealing with
         //               server-level privileges, since they're entangled with
@@ -1164,7 +1211,14 @@ begin
         sql := sql + ' ON DUPLICATE KEY UPDATE';
         sql := sql + ' ' + Delim(PrivUpdates);
       end;
-      Exec(sql);
+      try
+        Mainform.Connection.Query(sql);
+      except
+        on E:Exception do begin
+          MessageDlg(E.Message, mtError, [mbOK], 0);
+          Exit;
+        end;
+      end;
       // Special case: update redundant column privileges in mysql.tables_priv.
       if (p.DBOType = lntColumn) and dsTables.ColExists('column_priv') then begin
         // We need to deduce a completely new key because column_priv in mysql.tables_priv does not have a column field next to it, sigh.
@@ -1184,11 +1238,26 @@ begin
         sql := sql + ', ' + mask('column_priv') + '=' + esc(Delim(PrivValues, False));
         sql := sql + ' ON DUPLICATE KEY UPDATE';
         sql := sql + ' ' + mask('column_priv') + '=' + esc(Delim(PrivValues, False));
-        Exec(sql);
+        try
+          Mainform.Connection.Query(sql);
+        except
+          on E:Exception do begin
+            MessageDlg(E.Message, mtError, [mbOK], 0);
+            Exit;
+          end;
+        end;
       end;
     end;
   end;
-  Exec('FLUSH PRIVILEGES');
+  try
+    Mainform.Connection.Query('FLUSH PRIVILEGES');
+    ModalResult := mrOK;
+  except
+    on E:Exception do begin
+      MessageDlg(E.Message, mtError, [mbOK], 0);
+      Exit;
+    end;
+  end;
 end;
 
 
diff --git a/source/view.pas b/source/view.pas
index 7cddbe72..d7f884b5 100644
--- a/source/view.pas
+++ b/source/view.pas
@@ -159,14 +159,18 @@ begin
   if rgCheck.Enabled and (rgCheck.ItemIndex > 0) then
     sql := sql + 'WITH '+Uppercase(rgCheck.Items[rgCheck.ItemIndex])+' CHECK OPTION';
 
-  // Execute query and keep form open in any error case
-  Mainform.Connection.Query(sql);
-  // Probably rename view
-  if (FEditViewName <> '') and (FEditViewName <> editName.Text) then begin
-    renamed := Mainform.mask(editName.Text);
-    Mainform.Connection.Query('RENAME TABLE '+viewname + ' TO '+renamed);
+  try
+    Mainform.Connection.Query(sql);
+    // Probably rename view
+    if (FEditViewName <> '') and (FEditViewName <> editName.Text) then begin
+      renamed := Mainform.mask(editName.Text);
+      Mainform.Connection.Query('RENAME TABLE '+viewname + ' TO '+renamed);
+    end;
+    Mainform.RefreshTreeDB(Mainform.ActiveDatabase);
+  except
+    on E:Exception do
+      MessageDlg(E.Message, mtError, [mbOk], 0);
   end;
-  Mainform.RefreshTreeDB(Mainform.ActiveDatabase);
 end;