Fopnu 1.31 vanishes from the screen at random intervals and I have to launch the app again, on Windows 10 1809 17763.437 64-bit. Fopnu 1.30 did not seem to have this problem.

are you downloading/uploading?
are you in any channels?

is there a file being left on the desktop?
when you re-launch the program does it start normally?

did you try to revert back to v1.29 to confirm?
sometimes a windows update changes behaviors of some applications

I left fopnu v1.31 running on my windows 7 pro machine last night.
In the morning it wasn't running.
Wondering whether or not I forgot to restart it or something, i checked from another system. My client died about 5 AM. So it was an unattended crash.

The problem still exists in fopnu 1.32 on win10

Guest on 2019/04/16 08:32:07 AM, Guest on 2019/04/20, and BugMagnet:

are you all absolutely sure that your Windows OS did not restart?

my win 10 machine likes to restart on me.

quite sure it didn't restart. If it did, it would not start any apps until a user logged in to start a session. I could find no .dmp file for any crash.