[ERROR] FORGE MOD REJECTION

Hello, i'm new in this forum and i don't speak english very well, but i have a problem.

I created a forge server yesterday to play with a friend. When i start the server i can join without any problem but my friend is kicked and can't join
and tells him it's because "FORGE MOD REJECTION" and a list of a lots of mods. The problem is that I can join to the server but he has the same mods than me (i passed him my mods folder and the same forge installer that i used) and he can't. It's so rare.

Anyone can help me?

Thanks!

I adjunt a photo of the problem:

Hi, sorry for the delay.

The error has been fixed, we still don't know the reason but after deleting the .minecraft and installing everything back it worked.

Thanks for responding!