I'm working on tracking this down, but when I kill rifterrorhandler.exe and attach a debugger I'm not getting any crashes. And of course, the rift error handler won't share any of its information it will only send it to Trion and there doesn't seem to be a log of it.

So... if anyone wants to try killing the rifterrorhandler.exe processes (there is one per instance of rift.exe) and see if the crashes stop for them too... report back