mcreator 2020.2 1.12 won't load

Status
Can not reproduce
Issue description

I have 2 mcreator 1.12 mods and wanted to make another one to update the nether for 1.12 and the generator won't load but 1.14 generator will work

Issue comments

I was going to update one of my 1.12 mods and the workspace just wouldn’t open. It doesn’t happen in 1.14. It doesn’t matter now 1.12 is unsupported I switched to 1.15.