An old bug has apparently crept back in - after control L thjen return on the setting screen to start, a small white square appears and then nothing. Sometimes it happens several times in a row when trying to start a slide show; others only once; the majority of the time it starts correctly. Sorry, but I have not been able to pin down the steps to create the problem.
The same problem was occurring in PM5 and was fixed. In PM6 it started happening (I think) a version ago.
Win 10 Pro x64 filly updated
PM6 build 3954
NVidia GTX 1060 with Studio Driver 441.28
It is also happening on my laptop with one version older of the OS and a different NVidia card. Happy to provide details if needed.
Jerry