I had weird issue yesterday (Vu+ Duo 4K with OpenPLi 7.3).
Tuner was rebooted on Monday 14th because of upgrade to latest version (I noticed OSCAM was upgraded to r11606 If I recall correctly) and it worked fine throughout Tuesday 15th (yesterday). It made a few recordings during the day but when I wanted to watch them in the evening, I noticed that tuner was shut down (it started to boot when I pressed power on remote, rather just wake up).
It wasn't completing boot though - Vu+ logo was displayed first (on HDMI and LCD), then orange OpenPLi logo on HDMI, finally I had no signal on HDMI and LCD screen was getting black, rather than usual Enigma2 GUI... Remote didn't work. But it was possible to SSH into the box and OpenWebIF worked fine.
I soon realized that /etc/enigma2/settings file is the issue. When I renamed it and rebooted, box booted up fine, went through initial setup etc. I started making configuration adjustments, rebooting the box from time to time to checks if it is OK and it was fine. Until I made some final adjustments and rebooted and it again, then it fell into the same problem (sadly I do not remember what I changed in the last batch...)
I see nothing weird in the settings file. I haven't made any changes to settings in the past few days either. It hangs even if I use settings file from backups. So no idea what is wrong... Settings file was good and out of the blue became bad ? If that was caused by updates then it should start earlier, not yesterday.
Since I had some scheduled recordings for today, I again deleted settings file, went through initial setup and then made some really minimal adjustments and it works.
Any idea how to troubleshoot it ? I tried stopping Enigma2 form CLI (init 5) and starting via enigma2.sh but it returns no errors when it hangs... Just something about clearing Txt cache.