Hello. I use NixOS (linux), and I have found a issue the MyLittlePony theme.
First, I precise that I used a custom procedure to download the file (can be found here:
https://github.com/marius851000/mlpnur , download (with git or the release tarball), ensure you have nix installed, and run nix-build . -A my-little-karaoke in the root folder of mlpnur). But the issue doesn't seem to be related with this.
The problem is that, with the theme loaded at USDX startup, the game crash (at startup). Via debugging (with gdbgui), I found there were a key missing about EditOpenButtonFileName (or something like that). I solved the issue on my side by adding this (
https://github.com/marius851000/mlpnur/blob/main/pkgs/my-little-karaoke/patch_theme.ini ) to the MyLittleKaraoke.ini theme file (at the end). It mess up the microphone configuration menu, but at least, it start, and this mic configuration menu can still be used for first time configuration.