Sudden "An error occured", when playing with friends

[slavaxkt]

I've been playing with my friends for a good while now, since like, the beginning of this year. We're playing modded, of course, and we didn't have any issues before. But for whatever reason, when I try to join anyone now, or if anyone else tries to join me, it just says "An error occured", and we can't understand why. I'm using the very same mods that others use, I even tried using the thunderstore code that gives exact mods that I need. The wildest thing was the fact, that the issue was somehow fixed after I restarted my laptop, but it reappeared today, and this same fix no longer works. Does anyone know what could be the issue here?

[FineTripod]

Make sure everybody: 1. has the mods enabled, 2. Is in modded lethal company, 3. Has all mods UPDATED

[*****isshit]

Thank you Mr Beast!