The game crashed whilst rendering block entity
Error: java.lang.IllegalArgumentException: Cannot get property EnumProperty{name=axis, clazz=class net.minecraft.core.Direction$Axis, values=[x, y, z]} as it does not exist in Block{northstar:solar_panel}

Exit Code: -1

Crash log is visible here: https://pastebin.com/VfkK3AaJ

Until this is resolved, I have effectively lost one of my worlds entirely. If I try and remove the mod, the world becomes corrupted, but if I try to launch the save with the mod, it freezes and then crashes.

To save the world, remove the mod from your mod folder. Than download nbteditor off the internet and open your worlds level data and delete all the northstar dimensions in the dimension folder. Once you wipe out all the extra dimensions, you should be able to to open your world again! Hope this helps as I just ran into the same issue.