What mods do you have installed? I was throwing very similar errors and my issue was with one of my mods not being compatible with the new release. But with a little tweaking all is working good now.
I had these installed:
1386174080 - 300 Level
1159180273 - Fashionist v4.3.2
880454836 - Pippi - User & Server Management - v3.9
I had to replace 300 Level as it doesn't appear updated for the new version as of current. I replaced it with 2583216341, which is called Level 700, but it also is a 300 Level cap, but the developer actively noted it was ready for the new version already. For what it's worth, I uninstalled all of my mods, then reinstalled them one by one. But then realized that if I went to the "Mods" menu from my main menu, the mods that are built with the newest version will have a checkmark net to them vs. the ones that do not will not.
