RAM Elements Stuck in FEM Mode

Help!  I accidentailly clicked the Finite elements mode button on the toolbar, and now I can't get out.  I try and click it again to return to the normal view, and I get this popup:

 

Any help would be much appreciated.  I can't save, and have made some changes without saving and don't want to loose my work.

 

Thanks,

Tim

 

EDIT: The backup .bak appears to be older than the saved file, so that's a no-go.