This is a bug that prevents any end user (Guests or second players) to select a personal or default loadout, and selects the first one in the list automatically. When the “select loadout” button is pressed, (in my case Y) nothing happens, you can press it many times and no menu will pop. This affects all the online (customs work ok) games after the bug starts taking effect.
Today i was playing on the KOTH playlist and a game had just finished. Most of the players left, and the next match was going to be 5 vs 1 player, the game started, but the lonely guy left as soon as the game was loading, but new players entered the game at the same time… But the game had already ended, it gave us the victory but the other guys lost… 0 - 0 score. After that, i could not select ANY loadout in any online game at all, i pressed Y to no avail. Signed out and in, switched playlists and it did not come back. had to reset the game for the bug to be gone.
This bug has happened to some friends also on other xbox.