Merge remote branch 'origin/feature/7071_powgen_geometry'
Merge remote-tracking branch 'origin/feature/7139_SliceViewer_Crash'
Simplfy error message from Load when files are not found. Refs #6445
Improve error msg when a file from a range is not found. Refs #6445
Merge branch 'feature/6445_error_message_from_Load' into develop