Hello,
Whenever I try to add a keyframe in the 1.12.1 version of Replay Mod (using forge 1.12 - 14.21.1.2387), I get this error. I'm aware there is another thread about this issue in forge 1.8.9, but that user was able to solve the problem by opening the file using 7zip and deleting the file "entity_positions.json"
When I use 7zip on my replays, the only files that appear are "metaData.json," "mods.json," and "recording.tmcpr" so there is no "entity_positions.json" to delete.
I didn't find the right solution from the internet.
References:
https://www.replaymod.com/forum/thread/1732
app trailers