I recorded a replay, I go into it, writes a connection to the world, and it stays hanging like that, you can say indefinitely, and most importantly, the replay is in the background and I can’t do anything but close the Minecraft

If you haven't found a solution yet, please provide more details such as your Minecraft version, your ReplayMod version, versions of any other mods you're using, where the replay was recorded, and most importantly the latest.log file from right after you closed Minecraft.