Hassos boot problem UI not coming up

Since this weekend, I have a very strange issue. My hassos with latest updates installed including HACS and some integrations which ran fine last month on esxi now won’t boot up normally anymore. I tried a lot… I have the Samba add on installed and that always comes online so I can see my config files etc.
The only way to get my 8123 interface back is to rename the custom_components folder to something else… then it boots up with UI (8123). I have 4 custom components (including HACS). If I only rename 1 folder in custom components it won’t start either.
If started I can rename back and start the entire system and only reboot home assistant (not hassos)… And then all is up.

I am desperate… don’t know how to troubleshoot and where to start…

Please help?

I would start by looking at the home-assistant.log file in the config share via samba.

Thank you Micque, done that, nothing peculiar or abnormal or else than normal to see… I look there also a lot on normal circumstances.