Cant use every forge version above 1.11

[tekki2go]

I tried to install forge 1.12.2 and minecraft crashed

Then I tried some other versions, 1.13 and 1.14.4 crashed; 1.8.9 and 1.11 worked

[Ugdhar]

1.12 and really old versions are no longer supported due to age.

1.14.4/1.15.2 are the currently supported versions. The LTS link at the top of every page gives more detail on supported versions going forward.

 

Post the debug.log as described in the EAQ, for a supported version, and someone can take a look and try to give you a hand