As I understand it, I should be able to put CCCALENDAR with my other data bases on Filemaker 8 Server Advanced, and and serve up a multi-user calendar. My problem is, I (or anybody) can't create a new record.
The message comes up 'File is not modifiable'. The New Record menu is also dimmed. What did I miss?

Locally, it works great!

Sounds like you're on an OSX server and the file permissions are not correct. Go to the server and perform "get info" on one of the databases that IS working; turn down the detail arrow so that you see all 3 sets of file permissions. Now close CCCalendar on the server and perform "get info" on it. Change its file permissions so that they exactly match those of the working file. (Make all 3 permissions need to be the same: owner, group, and other- though I imagine it is "group" that is causing the problem.) Then re-open CCCalendar.fpy on your server and you should be all set.