was halfway through a run when i was adding in "oil burner" and decided to update this at same time and now i get an error message when trying to load into the game

"Failed to load mods: Error in assignID: technology with name 'f2pl-belt-transport-belt' does not exist.

Source: f2pl-belt-transport-belt (technology).

Mods to be disabled:
Factorissimo2-Playthrough (1.2.1)

What mods do you have enabled? It seems that something is screwing with the base game transport belt.

Have the same problem here, a bit of quick testing and found it doesnt seem to want to play nicely with Yuoki Industries Engines Addon, but performs fine with just the base mod itself
https://mods.factorio.com/mod/yi_engines

had this issue myself.. fixed it by getting rid of any Angels Mod and Artisanal Reskins.. dunno if that would work for you though