mod version: JustEnoughCalculation-1.12.2-3.1.0
forge version: forge-1.12.2-14.23.5.2808-universal

crash reports：https://paste.ubuntu.com/p/FC2XvHqyY7/

Thanks for report! Can you please try this one to see if it works?

JustEnoughCalculation-1.12.2-3.1.1-pre1.zip

Yes, it can works now.

Fixed in e87f2ad