** Using WeBWorK **

I'm upgrading an older version of webwork and noticed there are two courses that have long names (42 and 43 characters) which cause errors when trying to do "upgrade courses" from the admin home page. Apparently these courses were never actually in use.
The maximum table name length for mysql is 64 characters, and when the course name is suffixed with _global_user_achievement that limit is exceeded. But somehow the course directories were created but there are no tables for it in the db. So my question is is it safe to just delete the course directories?

Thanks!!