opening and viewing a ritual crashes the game

Hello, not affiliated with the pack owner. But it seems that there was a recent fix in Mana and Artifice Mithion/Mana-And-Artifice#411

Try updating the mod from 1.7.0.1 to 1.7.0.2 on your pack manager :)

We actually removed this mod on the newest update due to complaints, mob spawns and some issues in testing. You can try to manually just update his mod to see if that fixes it but make sure you update clients and server to the same version.