That sounds like replay recovery has failed for you (if that's the case, it should at one point have asked you whether you want to recover the file). If you're lucky and the replay file is still of sufficient size (multiple MBs) and/or you still have the original, you can upload it somewhere and I'll see if it can be recovered manually (assuming it's at least somewhat important for you).
I've already implemented some changes which will reduce the likelyhook of these kind of bugs once the next version is released. Until then, one good way to prevent replay corruption is to exit to the main menu and wait a few seconds to minutes (depending on how large the latest replay is) before exiting (or opening the replay).
all of the replay files that say 00:00 are 3-8 KBs. I don't really want them but it would be nice to know if they can be. And I'm not sure if it is just my Minecraft or the replay mod but when playing bed wars on Hypixel, Players don't render within a certain range. The distance is normally waaaaaay smaller. I can see a team base that is a good 100 blocks away but can only see players in a 30 block radius.
If the replay files are only a few KB, then there's probably not much (if any at all) replay in them.
I see no direct link between player render distance and the RM, does it only happen during bed wars or does it happen in any multiplayer session. Also, is this during recording or replay or both? Also, which version of MC, forge, other mods?
Sorry for the late response. I am running Forge 1.12.2 (220.127.116.1169), and I have Enchantmentglint, LunatriusCore, Optifine, QuickPlay, Schematica, 5zig, And Toro crafts Damage Indicators Mod (If you would like the exact files you can add me on discord SecondSword#5965). The short player render distance is only Bedwars as far as I can tell but only on certain maps like Doubles Steampunk and happens both during the recording of the replay and when I actually view the replay. I would be spectating my friend and as soon as I am like 40 blocks away he disappears and I exit spectator mode.