server error encountered after adding tag/gmail label

I'm running Version 1.9.5 (5260)

You probably need to look for any emails to which you have applied these tags and remove them. You might need the raw keywords column in the messages outline and you'll need to temporarily re-introduce the tags.

But we can also debug why it fails at all. What did you map these keywords to on the server (IMAP keywords)? It must be something that Gmail doesn't like I guess.

You can also generate logs for me by holding down ⇧ when clicking “Retry”. Send me the resulting file which is on your desktop.

Thanks in advance!

I actually hadn't applied the tags to anything, I just set them in preferences.

Retrying with a clean account setup, I'm seeing a slightly different error now.

1. Set up Gmail account (using an app-specific password, not using OAuth)
   
2. I see folders for my todo and follow labels appear in mailmate
   
3. configure a single tag in preferences:
   display name: todo imap keyword: todo gmail label: todo
4. do nothing else. don't apply tags or take any action, just wait.

within a few seconds this error appears:
MailMate encountered the following error: “Server response: “H11 BAD Invalid Arguments: Label name is not allowed: todo”.”.
Mailbox: “follow”.

log at http://pastebin.com/HxxgEjEu