Just happened again. I went to the Windows Event viewer and it looks like it's the 17.1 webapp crashing. Hard to tell since the path is shortened in the the report, but I could see 1.1 in the path name - which is probably 17.1

I used to have this happen on web servers before and it always seemed to this Xalan-C_1_10.dll that crashes. Or perhaps an earlier version. This dll is from Adobe from my research.

Also I wasn't actually running an web app in a browser at the time. My past experiences with this dlll crashing seemed to be related to some web services I had running.