If OpenIV or a mod manager corrupted your original dlc.rpf , you need a clean or updated copy to restore functionality.
Right-click Grand Theft Auto V in your library > Properties > Installed Files > Verify integrity of game files . Update X64 Dlcpacks Mpchristmas3 Dlc.rpf Download
Modders typically need to update mpchristmas3/dlc.rpf for the following reasons: If OpenIV or a mod manager corrupted your original dlc