Main Log

The world starts to load, then the game errors and boots you back to the multiplayer screen, even if loading a singleplayer world. It seems there's a malformed packet somewhere.

EDIT: And removing this mod allows the world to load.

This isn't the first time I see this error... unfortunately it's caused by the sheer number of spells and how EBWiz itself handles spell data syncing. It tries to synchronize data (server->clients) in a single packet, but with so many spells (from multiple addons), the packet is being broken into multiple parts or truncated, causing this error.
Key takeaway, I'll try to fix this from the EBWiz codebase by splitting up that packet into e.g. batches of 100 spells.

Sounds good to me. Also, Merry Christmas!

Fixed in Electroblob77/Wizardry#750

Should work fine in 4.3.6 Wizardry