I am not sure, but I think I read about a similar case where the issue was a specific word in the mod file name - here in this case it is "true"
This has something to with mod loading behavior
Rename it to northstar-north-1.1.0.jar and it will work
If you rename it to true.jar or true-1.1.0.jar, the game will crash - even if you name it false.jar
I am not that deep into mod developing - but I think this is some kind of "expecting String instead of Boolean value" syntax issue somewhere deep in the modloading process (mixin configs, metadata, class scanning etc.)
So I think this is some kind of Java issue, not Forge itself 🤔