It seems that when another mod (Tinted) adds new dye colors, Just More Cakes looks for the new candles variants in the vanilla namespace instead of the Tinted one. Since they don't exist, the game crashes.

crash-2022-11-11_06.55.41-client.txt

(However, the problem may lie with the method Tinted uses to save its new colors, I don't know how it works)

Hello. Thanks for reporting this. After some experimenting and looking at released code and currently unreleased code it would seem that I unknowingly already fixed this and just need to release it to curseforge. It also seems that I unknowingly added support for Tinted with the way JustMoreCakes is set up and just need to create the assets and data to finish making everything look and work right