I found two solutions. I applied them both simultaneously, so I don't know which one worked, but I'm documenting them here:
Solution 1:
I set my group policy back to defaults as per this page:
http://forums.whirlpool.net.au/archive/1533833
I did this (copying the solution in case that page ever goes away):
- dcgpofix /ignoreschema
- Press OK twice and run gpupdate /force
- Reboot
Interestingly, my drive mappings group policy stayed in effect. However, my password policy group policy settings were removed.
Solution 2:
I removed all of my event logs as per this page:
I'm writing this a couple weeks after the incident. I don't remember not being able to open the event log, but I was in a panic as the issue was occurring during work hours, so I was throwing the kitchen sink at the problem. To accomplish this task (copying the solution in case that page ever goes away), I did this:
- Stopped the event log service
- moved all files from %systemroot%\system32\winevt\logs to another location
- Started the event log service