Hey mr fister, I come to you today with a bug most likely with your mod, although I can't be 100% certain I thought it worth mentioning as I use a very small amount of mods compared to others.
I've had this server for 2 weeks now, and only today did it start crashing, 4 times within the space of a few hours, 1 time as soon as I restarted. Naturally I contacted my provider whom pointed at the issue being mods as they always do, so I thought about it for a bit rather then just disabling them left and right. Due to more and more players joining over the weeks there would be more and more fog removers removing fog, so I thought removing it would have the least impact on the player base and so I did, few hours have gone past now and no crash.
The map is Ragnarok, the amount of fog removers? well each person is capped at buying 5 (through a shop plugin) and I never saw them abused, just everyone had 1 or more. I'm not sure if it can be replicated by placing 1000 of them due to it all being the same player, I think it may be due to different owners? Anyway feels bad with fog now :(