Here is a paste bin of my log: https://pastebin.com/X4QnaWge
When ever I start Minecraft forge 1.12.2-14.23.4.2705 it begins to load up like normal with its 7 step process, but once that process finishes it tries to bring up the Minecraft main menu and just crashes. When it crashes it gives me the crash error:
The game crashed whilst rendering screenError: java.lang.NullPointerException: Rendering screen
I tried a normal Minecraft version of 1.12.2 and it loaded fine.
I tried another version of forge, being 1.8.9-11.15.1.1722 which loaded fine.
I have tried reinstalling the version of forge I was using but it gave me the same result of crashing at the Minecraft main menu. The menu doesn't load, it is just a screen of the dirt texture before it loads when it suddenly closes and kicks me back the launcher.
I was playing the same forge version about 15 - 20 minutes ago fine until my game crashed, which most likely caused this problem. I went into my logs to see if I could provide the log for the last game I had played where it crashed, but that log was just gone, there was no log.
If there is anymore information that you may need let me know and I will be happy to get it for you.