when creating a new world if you look into the data pack folder it marks it as incompatible wich leads a pop-up menu saying to try loading the world in safe mode or go back to the title and remove the data pack

I am Having the same problem as this. Tried Reborn core .35 and 49,and Tech Reborn .48 and 72 cant load or create world when I disable them it works set them up again it says this and for me safe mode will not work ether.

:Edit Just tried Reborn Core .49 without Tech Reborn and it work just not with Tech Reborn.