Hi guy, I come here to post, because "Zemurin" from steam community have guided me to.
Okay, the thing is that, I tried to convert my Aztec Empire from CK2 to EU4, with "de Foix", but the game couldn't be loaded because there's a bug of converting High American techgroup. (BTW, I have bought Leviathan dlc, looking for converting CK2 wonders to EU4 monuments)
Here's my CK2 save, it converts normally under EU4 1.30.6 with "1.0Este", but failed under 1.31.0 and 1.31.1 with de Foix. I am gratedful if you guys use it for a test.