So i have downloaded the server files by the FTB Website. On my Pc i started the Serverinstall.exe. the Serverinstall.exe created the server data like: the config, libraries, mods and world folder.
On the Server where i get the error code i installed Forge Vanilla. Then i have overwriten the Forge Vanilla with the data from my Pc...
With the ,,i didn`t change any code`` i meant, that i haven edited anything by hand.