Hi. Although it is a wrong thread to look for help in, I will happily answer you :p
As far as I know, there are still plenty of events in NW. The community of this mod, however, moved to a different forum (fsegames.eu) so if you want to find clans and events for NW, I suggest you visit this site.
Apart from that, there is also Native community, but events do not seem to be very popular there. AFAIK, there are several tens of more or less active clans, as well as a few tournaments, where clans play matches against one another.
When it comes to other mods, it looks like PW servers are quite populated every evening, so maybe you should try finding a clan for this mod? If you don't know PW, it's some kind of a MMORPG on Warband engine (if I'm not wrong). There is also the Deluge mod, featuring wars in 17 century eastern Europe. There are always some people playing every evening, as well as larger events organized by Halsingland clan every Sunday with 50-150 players.
When it comes to Vikingr - random plays on a public server ended more than a year ago. There was a short comeback when the Community version was released, but it seems to be dead again. My event was being hosted from January to October this year, but to be honest, I lost enthusiasm to Vikingr for now, and am not planning to bring this event series back to life in the nearest future.
If you cannot play MP in Vikingr, you must have done something wrong, although it's not easy for me to see why. Hopefully other people here will be able to help you.