Actually, there's at least one folder that causes the error.
Maybe they are several but ZCS stops on the first one...
Check the link: do you have "not standard" folders (such as "outbox")?
About deleting folders from CLI, you can do it with zmmailbox command. Check the wiki for how to use it (list folders, get ID and delete them).
However, I don't know if it will fix your issue.