java.lang.NullPointerException: Null string not allowed
at java.util.Objects.requireNonNull(Objects.java:228)
at net.minecraft.nbt.NBTTagString.(NBTTagString.java:19)
at net.minecraft.nbt.NBTTagCompound.setString(NBTTagCompound.java:138)
at com.denfop.tiles.panels.entity.TileEntitySolarPanel.writeToNBT(TileEntitySolarPanel.java:345)
at codersafterdark.reskillable.base.LevelLockHandler.rightClickBlock(LevelLockHandler.java:334)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_3133_LevelLockHandler_rightClickBlock_RightClickBlock.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
at net.minecraftforge.common.ForgeHooks.onRightClickBlock(ForgeHooks.java:1137)
at net.minecraft.client.multiplayer.PlayerControllerMP.processRightClickBlock(PlayerControllerMP.java:398)
at net.minecraft.client.Minecraft.redirect$zba000$rightClickBlockProxy(Minecraft.java:3362)
at net.minecraft.client.Minecraft.rightClickMouse(Minecraft.java:1579)
at net.minecraft.client.Minecraft.processKeyBinds(Minecraft.java:2254)
at net.minecraft.client.Minecraft.runTickKeyboard(Minecraft.java:2020)
at net.minecraft.client.Minecraft.runTick(Minecraft.java:1808)
at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1098)
at net.minecraft.client.Minecraft.run(Minecraft.java:5114)
at net.minecraft.client.main.Main.main(SourceFile:123)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.polymc.impl.OneSixLauncher.invokeMain(OneSixLauncher.java:104)
at org.polymc.impl.OneSixLauncher.launchWithMainClass(OneSixLauncher.java:175)
at org.polymc.impl.OneSixLauncher.launch(OneSixLauncher.java:185)
at org.polymc.EntryPoint.listen(EntryPoint.java:144)
at org.polymc.EntryPoint.main(EntryPoint.java:74)

Check in RC7

fix