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What version of Forge is installed on your client? If it is different from the server version (you have 28.2.0), try to install it.
And are you sure that the version of the mods is the same as the one on the server?
What version of Forge is installed on your client? If it is different from the server version (you have 28.2.0), try to install it.
And are you sure that the version of the mods is the same as the one on the server?
Yes, the version of the mods, the server and my client are the same.
Yes, the version of the mods, the server and my client are the same.
Forge, too?
remove mods one by one, after each one, restart the server and try to join it. If that does not work, remove another one and go on like that until you can join.
Okay everything works now, thank you guys! 
