TheWesleyOne

Except that I have had no other problems installing any other mods (not reliant on Forge)

I'm still in need of help my problem has not been solved

I grabbed a new copy of mincraft_server.jar rename it to minecraft_servercopy.jar, open minecraft_servercopy.jar and minecraftforge-server-3.3.7.135/minecraftforge-server-3.3.8.147 put all the files from the latter in to the former run " java -Xincgc -jar minecraft_servercopy.jar" and get the error above.

Now it spewed out even 3.3.8.147 give me the same

I downloaded A fresh minecraft_server.jar from minecraft.net installed "minecraftforge-server-3.3.7.135" only, now my server will not even start.