Repeat:

• Work on a git project,
• If somehow you manage to have a merge conflict in a .qrc file,
• Then QtC hides it from the tree,
• Then try File->Open File or project, open your .qrc file, you get a blank dialog with zero useful information
• The you go to: File -> Open File with..., try to open the .qrc with the resource editor. You get the same blank dialog with zero useful information.

I know it is corrupted, but if you manage to corrupt it you dont get any clue about it. At least say:
"The file is corrupted, it will open it with the Plain Editor [OK] "

Then open it with the plain editor.