Hello, i am using mp3tag on Mac vers 1.8.21
The tag source Soundcloud WS is giving me this error message
ERROR(L24): unknown command 'debugwriteinput'.
It's basically what the error message says, the debugwriteinput command is not available on macOS (but also not needed for the Tag Source to function).
It's not recommended to leave debug commands enabled for released Tag Sources, so you could ask the developer from the original topic to remove those commands. In the meantime, you can remove the mentioned line.