Minecraft 1.9 was a thing. I tried it. It was fun. Decided to go back to my modded worlds because vanilla just feels so... vanilla.
Forge profile is no longer in launcher. Okay, I'll download and install again.
The installer will download just fine, but my computer refuses to run it.
I opened a terminal in my downloads folder, typed java "forge-1.7.10-1.13.4.1558-1.7.10-installer.jar" to try and run it directly, and received Error occurred during initialization of VM java/lang/NoClassDefFoundError: java/lang/Object as a return.
I understand very little of java, but I tried manually setting the classpath to the folder I had placed the .jar in, and received the same error.
Any help would be much appreciated, as right now I can't install or use Forge.
EDIT - I facepalmed REALLY hard when I realized what happened.
Java couldn't find its own .lang file. After reinstalling java, it runs just fine.