RS 2022.
Okay, this is weird. I have a simulation that was working perfectly. Then I went into the Rapid editor and added several subroutines to use Clock variables to record the duration of different segments of the sim path. I've done the same thing in other sims without any issues, but on this simulation, when I run the sim, it runs once, but at the end, the "simulation" tab keeps blinking green, the Sim tab buttons seem to show the sim still executing, and the virtual controller goes into System Fail, with no clues as to what caused it.
I can't reboot, backup, open the virtual pendant, or save the station -- the only way I've found to get out of this is to close RS and re-start. And when I open the station, I get an error that the modules in the Virtual Controller do not match the last autosave, and the RAPID compare tool comes up automatically. And the Compare shows that what's in the VC is the code from before I added the time-logging functions.
There's nothing in the message window aside from "failure state" (ignore Robot B, that one's not set up yet, only Robot A is running)