Symphony.

This was rather random. Today while working with symphony 2 this error popped up:

Fatal error: Call to undefined function datetimeobj() in portfolio.jon-kyle.com/html/symphony/lib/core/class.log.php on line 133

I wasn't editing any code when this happened, and it has brought down my entire symphony instillation. Any ideas?

Yes, I'm not sure as to why it happens when it does but it's an easy fix:

http://bugs.21degrees.com.au/comments.php?DiscussionID=110&page=1#Item_0

There's a warning that occurs when symphony tries to set the author's "last_seen" entry in MYSQL. Symphony has a max file size limit and it will try to save the main log file into a .zip. Saving into a .zip you get the L133 error.

Correct. That warning has also been fixed for Revision 5.