Fatal error: Could not load class tl_calendar_events

[Logan]

I'm getting this message when I try to edit user groups:

Fatal error: Could not load class tl_calendar_events in /home/npcccc/public_html/system/functions.php on line 67

What could the problem be? Everything else appears to be working fine.

I have just installed two extensions:
- Extended Typolight backend
- Tags extension (by Helmut Schottmüller (hschottm))

Could these be causing the problem?

[Logan]

I just noticed that when I go to create a new module, there's a category of "events" with a single module choice of "events list" and none of it is capitalized or anything. All the other modules have proper capitalization.

This lead me to believe that there was some issue with the "Events" extension. So I went into "Settings" and saw that I had deactivated the "Events" extension because we weren't using it. I activated and it and viola! I can now edit "Member Group" settings. Just to make sure, I went and deactivated "Events" again and sure enough, I couldn't edit "Member Group" settings again.

So my issue is fixed. I can edit member group settings, but this seems like a bug to me. Is this a bug of some kind?