Yes, i see this fix in 17.7 patchn notes
We have new problem on multiplayer
Launch server with mods (headless or win, no matter). Run occurs correctly, based on the logs.
But. Anyone trying to connect to the server gets an error.
For each mod, using in modpack, show messages:
1. You need mod: N
2. Mod N missed on server
Without mods server works correctly.
I am looking for a messages in the main thread of the forum.
Continue playing 0.16.51 and wait for correct 0.17 multiplayer