maybe with some interes for some people here trying to debug all the errors they get upgrading to 4.0. I found a command line tool wich i love it so much so i just want to share to others maybe they find it usefull.
in your debian install is as simple as sudo apt install lnav and then to open the logs files just use it like this:
lnav /var/log/openhab/openhab.log /var/log/openhab/events.log
it will highlight errors in red and warnings in yellow by default but it can be customised further if needed
-to move just press e to go down the list trough errors or E to go up the list trough errors same for warning
-by pressing the tab and then i and inputing a specific item name then enter and q and after using the arrow keys will allow to see all entries in the logs