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
Obviously not as outdated and modded versions are not officially supported.