2019-07-29-4.log.gz

The RM bundles an older version of the Mixin library than another mod requires. Try renaming its file to start with z, so it loads after the other mod.

Err, what does that mean? Which folder do I need to rename?

The ReplayMod jar file which you downloaded from replaymod.com starts with r whereas the one from the other mod starts with s (iirc) which puts it after the RM in the load order causing the older mixin bundled with the RM to be loaded. By renaming the RM jar to start with z, the more recent mixin bundled with the other mod should be loaded instead.

Thank you, that helped. All I had to do was stick a 'z' at the start xD

latest.log
I'm having some strange issue where it wont load the mod at all. I currently have it with a z at the start. I've tried it with nothing but the mod and forge, still nothing. Any thoughts?

@Chris221 Same thing but the other way around. LiteLoader ships a Mixin version which is older than what the RM requires. Since liteloader isn't a normal forge mod, you can't just rename its jar file to change the load order, instead you'll have to ask on their issue tracker.