Tested on MC 1.12.2 with Replay Mod 2.5.2, 2.5.1, and 2.4.5.
Modlist: https://pastebin.com/u9PjEcgT
debug.log: https://pastebin.com/Sfvi4A6J (only the last ~1200 lines due to file size)
latest.log

I've spent multiple hours trying to get this mod working with the Chroma Technology modpack. Essentially, the game freezes and does not accept any inputs. However, the GUI is still responsive (ie: buttons hover animations still work). All other functions of the mod work as intended, but I can't pause nor scroll through the replay without it freezing. I've identified the following mods which could potentially cause problems:

• RandomPatches-1.12.2-1.22.1.10 (disabled from the start since I know it's not compatible)
• ResourceLoader-MC1.12.1-1.5.3 (disabled from the start since I know it's not compatible)
• BetterFps-1.4.8
• VanillaFix-1.0.10-150
• TickCentral-3.1

I've tried disabling those mods (as well as some other mods) and the same issue occurs no matter what I try. I tried enabling quick mode before pausing but no dice. Doesn't matter if I pause using the pause button, the P keybind, or by pressing escape.

From looking at the log files, it looks like a NullPointerException occurs when loading the replay, not sure if it's related. In the debug.log file, when I pressed the button to pause it was after I enabled quick play, and there's nothing displayed in the logs related to ReplayMod after that.

There's also this line [17:25:03] [Thread-143/ERROR] [com.replaymod.replay.ReplayModReplay]: Could not load Replay File 2021_03_19_16_38_15.mcpr but that's because I unloaded some mods between attempts. I always create a new recording between attempts so that the mod changes does not affect the problem.

Based on the last major exception in the log, looks like this is caused by a bug / incompatibility in "discordcraft". If removing discordcraft fixes the issue, please report it on their issue tracker. Otherwise I'm afraid you'll have to go through the time intensive process of narrowing it down by removing half the mods at a time till you're down to just the conflicting one(s).

Unfortunately removing discordcraft did not fix the issue. The latest.log does not show any other error besides JourneyMap (which I've tried disabling as well) when I open the replay. Not sure I really want to take the time to narrow down which mod is causing the issue but if I do, I'll post an update on which mod caused the problem.