Steps to reproduce:
- have a model opened (or just create one)
- save it
- trigger the menu item for 'Reload "bla.model"'
- change something [add or remove some element(s), change the position of some elements... whatever]
- trigger the menu item for 'Revert "bla.model" to Saved'
- in both cases you'll get an error message box stating that QC cannot reload the model file