I was fiddling around about a month ago and started tinkering with virtual folders. Long story short, it did not go over well.
I updated to 1.90.1 (1.90.2-SNAPSHOT is what I've tested with tonight) and this spawned the HTTP 500 Error.
At least it only does so from .rar files now.
I removed the vfolders line completely from PMS.conf and rebooted both PMS and then the entire computer.
When that didn't work, I uninstalled and reinstalled the server software.
I have updated Java to 7.0.40 both 32-bit and 64-bit tonight, which Java said I needed to if I run a 64-bit machine.
I tried the new tempdir solution I found in another thread about this issue.
Extracted files work just fine, but not so much from .rar files anymore.
From what I can find in the debug.log, there's a java pointer gone awry somewhere and somehow, and this is messing with the extractor. I could be wrong.
I would very much appreciate any pointers (no pun intended) or advice you can give me about this.
Contents from debug.log pasted below: