Your project simply works here. (Windows 10 and Debian Linux too)Code: Pascal [Select][+][-]uses Clipbrd; procedure TForm1.Button1Click(Sender: TObject);begin Clipboard.AsText := 'Lazarus is great'; Edit1.Text := ClipBoard.AsText;end;IOW, Your code should work and I can't explain the sigsev. What versions are you using? (Windows, FPC and Lazarus).