Minecraft 1.12.2 Forge no longer starts! Solution?

Me and my buddy wanted to play some mods on my server today. When he started the game nothing came, we waited half an hour then the game crashed, we tried a few tutorials but none helped.

Can you help

Without detailed error message? Without information about what you've tried? Without specifying which mods are on it and in which versions ect? And without a glass ball? Nope… That would be guessing and poking around…

Didn't write everything so I'll take pictures of error messages

Mods are just immersive engineering flans mod buildcraft tech guns and nothing else

Yes the newest 1.12.2 forge

Have in my 1.12.2 pack on the latest forge version problems with the flans mod. Also crashes. Ka why, try a different flans mod version or without. Techguns has better weapons anyway.

Is due to the flans mod. This is generally extremely incompatible with a lot of things. The modder doesn't itch.

Ka, it's not funny with me

But he can't play other mods either