The code in my local machine (to be commited later) refers to the main window UI class as EchidnaEditor, although the ui file still uses MainWindow, Qt Designer's default class name.
I was confused so much by the error message, until I realized the issue was this.
Anyways, this includes the "fix the sidebar tab that isn't a proper tab". Should have commited this in a separate commit, but Git won't let me.
Should have commited this earlier. Same thing with e0ba34d.
Nefo Fortressia
d6462907f1