So, if I try to open old realms/server replays that are pre 1.21.3, they don't open and display network protocol error, and If I open old single player recordings from pre 1.21.3 they open, but get stuck in a reloading loop whether I pause or play them.

disconnect-2024-11-14_12.49.05-client.txt
I don't know if the disconnect shows other mods interfering or not, but I tried this with no mods but replaymod and fabric api and it still happened.

Same issue here. Seems to be with a specific replay file.