Not sure if this is something I can bother you here with:

I installed Forge 1.8.9 in order to get "computercraftedu" running, which seems to require this old version.

First I got stuck as "jopt-simple-4.6.jar" was missing and couldn't download, but i added it manually in according folder. After that, it finished downloading, but always crashes, no exception. I tried both available 1.8.9. subversion, no difference.  Crash file attached.  Minecraft at latest version