I had the flight plan from Navigraph manually entered into the FMS (without the hold). Then in flight I went to the HOLD page and selected ERNOV. The hold was the wrong heading, so I tried to change the radial. The scratchpad emptied and EXEC and CANCEL MOD showed up but the radial didn't change. If I clicked on EXEC or CANCEL MOD, they would disappear, with the radial unchanged. Same exact thing with the inbound course. The leg time I was able to change as expected. Then I went to the LEGS page and clicked on the first waypoint after the hold (CH886) and the sim froze. I had to end task in Task Manager. This was all before I actually reached the hold.
As a matter of fact I'm not sure how I tried to enter the radial and inbound course, but I assumed I'd done it right, because EXEC and CANCEL MOD showed up, but even if I entered them wrong, the freezing of the sim is at least still a problem.