This morning I tried relaunching 2019r2.1 & 2019r1.1 and no error message. All works normally. I haven’t even rebooted my machine.
Now I remember something else. Yesterday my screen saver wasn’t kicking in after the usual 7-min inactivity pause I have it set to. That’s usually related to a memory consumption issue. The screensaver is back and Xojo now loads normally.
I’ve seen similar issues in Windows 10 over the past few days. It appears that the NTP functionality is a bit hosed and the system clock is getting twisted. I keep having to go back to the Windows settings and turning auto timezone off and back on. It also affects any version control apps you use.