Because the mod is updated and as mentioned, saves are not compatible with the new version, you need to revert back to the old version sir.

Tried reverting, still crashed for me unfortunately. Though I have some more mods, so can't say for sure it's just ET.

I didn't update and I#m still on the old version. Nevertheless it is crashing.

Ok, what worked out for me (so far?!?), maybe of help for others: I updated the Game to 1.36.0 and forced the game to load my old file, although it said, that my version is incompatible.

Originally posted by Saul:

Because the mod is updated and as mentioned, saves are not compatible with the new version, you need to revert back to the old version sir.

Is their a way to revert to the previous version of the mod or am I limited to only being able to revert the game itself?

I experience the same today. When EU4 updated to 3.6 I reverted back to 3.56 and no problems. But today neither 3.56, 3.6 or up to date version breaks my game. Lost all my vassals and it pulled me out of a big war I'm about to win etc. If someone has a fix, I'm all ears, otherwise it's 2 weeks of gaming from a OPM at the earliest date to 860 wasted...

If you open the game normally and then pick a save then save the game it causes this. If you don't click single player and just load your last save this doesn't happen. I don't even know why it's like that but it works.