It appears mission cache data can cause more and more instability as time goes on.
user/appdata/local/arma3/mpmissioncache
My theory is that some missions are either causing bugs or multiple missions stored in the folder are trying to be used at the same time when in a multiplayer game. I imagine that if two mission files were used at the same time in a mission.
My stability got worse and worse. The first day I played no crashes, the next day maybe a crash every 20 minutes, after that every ten minutes. Deleted my cache then played fine for a while till I believe a certain deathmatch server gave me a bugged file. Deleted cache again and have gone about 2 hours with complete stability.
Some mission files are just buggy, if a server crashes you frequently delete the mission cache files. You can try that server again and if it keeps happening, delete your cache and avoid that server mission.
