This is modded community server, and mods might get updated and not being downloaded automatically for You.
• please read your warning text and check for missing or outdated version mod name,
• restart your steam client to force download new steam workshop updates,
• if this is not working, try updating your missing or older mod manually by using repair function in Vanilla DayZ Luncher (MODS tab) or verify function in DZSALuncher (Mods tab),
• if you are still unable to join the server, contact server administrator on Discord (this might be server-side or mod problem).