Archive to Gmail Fails, but only when using the Archive Button on the Toolbar If I try to archive an email using the toolbar 'archive' button I get this error message:

"The IMAP command “UID COPY” (to Archive) failed for the mailbox “INBOX” with server error: No folder Archive (Failure)."

However, if I manually drag the email to all mail, it archives just fine.  Any ideas?
Go to Mail.app / Preferences / Accounts / MailBoxes and under Trash, uncheck Store deleted messages on the server.

Usually this does the trick.