Using latest Fabric and Fabric API for 19w35a.
And the mod is also the latest of 1.15

If i create a fresh new world,it will not crash.
So i think is the problem is SolarPanel

I havent updated it to 19w35a, 19w34a will work. I will get around to this at soon.

I’ve released a 37a build. Don’t expect me to keep up with all snapshots, possibly every other one just to keep on top of updating.