Hi,

You are right, it's not allowed do import other libraries from UI, but some of them are already imported, like datetime or UserError.
So you can just write UserError("Needed value") and get a result. It working also in scheduled actions.

If you are doing from the UI side you don't need to import it just use
raise UserError('Hellooooo')

i added code as below:

abcd = self._origin.id

    raise UserError(f'{abcd}')

here is screenshot of error:

regards