Marco:
I have more information for you.
The problem occurs after I restart my computer and run Delphi. If I try to access any form or data module with DOA components, Delphi stops with the message: "Codegear Radstudio for Windows has stopped working".
Restarting Delphi makes no difference. However, dropping a new TOracleSession component on any form stops the problem from occurring.
Once this has been done, I can work normally. The problem does not occur again until the computer is rebooted. So exiting Delphi and restarting is not a problem.
Thanks, Sidney