@dnkl https://github.com/audacious-media-player/audacious/pull/1597
TLDR: audacious removed support for opening directories via a file manager.
Some mis-configured DEs don't configure a default file manager, and use the first program (sorted alphabetically) to open directories, so audacious is used when opening a directory.
Instead of fixing the broken DEs they just dropped support for opening directories in audacious.
The proposed solution is just patch the file yourself, and keep patching it, for the rest of your life.