I have solved the problem:

I delet the mod folder on the server and uplode my local mod folder to the server. Server restart --> We all can join the server without desync.

Maybe same other people can help this.

Rincel

Hi, the last 3 Months we played without problems. We don´t change anything. Today (16.06.2019) i can´t conect to server (Nitrado). (Desyncs) I have tryed a restart and i have update the mods (3). No result. I can play local both version with update Mods and without. Modlist: alien biomes 0.4.14 --> ...