If tax client appears to close when selecting F8 or going to Account notes screen. 

1. Open SQL pull up the data on the account in the accountnotesxref table and the notes table by lNoteID.

2. If there is no data in the lnoteID table the issue is with the delete button in the notes screen.

Solution delete the record from the accountnotesXref table. 

Then bring up the account again, to confirm the issue has been corrected.