I think I faced exactly the same thing as you yesterday. I got an error message where it said something about the audio, sorry don't remember the error message. I tried a few things and gave up and just installed everything (Raspbian and Retropie) again. It should be another way though..... Its absurd you have to reinstall an OS because of this....
Great, glad it's working.
I removed the vc4 workaround stuff since it's not needed, and changed the init_delay to use seconds rather than milliseconds, since it's totally more useful with seconds (if people use video splashscreens).
The installer script was also updated to have a brand new file/directory selector for the initial song and music directory options, making them actually usable without having to pull out the keyboard.
Change Music Dir
Also fixed an issue with spaces in file paths and fixed some smaller niggling things (stopping used to spit out "Terminated blah blah...").
The only thing I'm planning at the moment is to maybe dynamically come up with some nice volume step values based off of fade_duration and max_volume to make just that little more "user-friendly" and remove that config option.