Hi!
I'm on Minecraft 1.21 with Fabric loader 0.15.11 and Fabric API 0.100.3 and when the mod is installed I can startup the game, get the Mojang loading screen, the music plays, but I can't go any further, the loading screen halts at about 80%.

See latest log here https://mclo.gs/qrDQiZR

I have predominantly 'Fabulously Optimized' and Masa mods installed.

Thanks for your help!

Edit: I installed a new FO instance and went down the list. Seems that Entity Model Feature version 2.1.3 causes the problem. If I disable it, I get the main menu.