Can't delete mail.mac messages


Each time i try to delete messages in my mail.mac account an unexpected error occurs:
An unexpected error has occurred that may cause Mail to malfunction. You may want to quit Mail.

Error: *** -[NSCFArray addObject:]: attempt to insert nil

Any idea?
How are you trying to delete the messages? Are you clicking the delete icon in the toolbar, pressing delete on the keyboard, or dragging the file to deleted messages? It might be complaining about the method you are using if you are trying to drag the message to deleted messages. If your pressing the delete key or toolbar item then the deleted messages .mbox file in you ~/Library/Mailboxes/ directory may be corrupt. How it would get corrupt is beyond me.

I have not had this problem personally, but I figured I would give you a few possible solutions.