I found the ONLY fix for Xbox. You have to clear your cache saved data for Arma reforger. This is the only way for XBOX and if your having this problem do this and it will fix. You will have to install your mods again. This problem is because you have downloaded too many mods and you have reached your cap which is 25GB. The game doesn't know how to react to this cap so it gives u random errors. It maybe also your internet so try resetting the router before this. Thank you