(As for e107v4a vs hanging (you mentioned another dbase used, so there would have been issues too?)
Anyway both are not up to standards for v2. and if dbase would hold V4a, than hanging should not be running....all very strange; best to test again with v4a (as was in dbase) (although incomp) , as it uses different layouts (displays different)..
I can see more errors now, although theme (hanging) is present..
This looks like can not be solved by communication.
I could help but that would be having access on all levels (dbase,server (ftp) and admin privileges).
That is up to you. (ps never credentials in public in case this would happen but pm).
But question still is unanswered > what where you running before the upgrade?and do you have any backups? Did php versions change? (can you switch back to php 5.6 f.e.)
Preferable database(s) and files.
The google ad thingie is also an issue that could havoc..again insure.
I now can see more errors going through pages like (Fatal error: Uncaught ArgumentCountError: Too few arguments to function) it all seems to point to plugins in use (older ones messing up) that conflict with shortcodes (maybe theme has/uses them,> 'hanging' uses such and plugins?? ).
All in all pinpointing is too difficult as there have been incompatible changes or update routines which can be versions from ..to or php version issues..