"Audio bitrate is higher than 192kbps". I would change it, but I've made a lot of progress into the map, so is there any way I can keep the map and change the mp3 file used?
You can just compress it via external programs such as audacity, there are tutorials out there including here somewhere on the forums. You can change the mp3 of a mapset just by naming the new mp3 like the original one (which can be found in the mapset folder)
Download Audacity Open Audacity Open the song in Audacity Export the song in Audacity, you'll go to preferences Set the file to .mp3 with 192 Kbps and give ot the same name as the old mp3 Once it's done, open the map
The offset changes a bit (like 20-40 ms), so you'll need to move all objects/timingpoints!!!