Yeah same problem. Not sure why we can't use chat to notify everyone to report a bot after we've died (I dont have time to report that while playing), so I had to remove this mod.
Game won't load after using modpack 4.0
After multiple tests, unchecked ServerCross (server crosshair, must enable in game menu!) under the Crosshair Mods section and everything worked nominally.
Have a great day!