When you go into a task to encrypt a file, you select the recepient then you select the signer. When you come out of the task and job, you go back in and select the task again, if you try to exit it, it gives you a prompt that says 'you must select a signer'. If you make a selection and click 'ok' and get out of task, it will keep giving you the same message every time you go back into the task and get out.