Error: Error opening feature class. Invalid spatial reference.
Attempting to add a personal geodatabase feature class to ArcMap produces this error:
"Error opening feature class. Invalid spatial reference."
A discrepancy between Input Locale and the Numbers settings in the Regional Options Control Panel can cause this error. For example, if the Decimal Symbol and the Digit Separator Symbol on the Numbers tab is changed, without changing the Input Locale to an appropriate setting, the error occurs.
Solution or Workaround
Change the Input Locale setting to an appropriate location for the number separator symbols to be used. A number of locale settings may need to be selected until the one that uses the symbol settings desired is found. For example, if using comma separated decimal numbers is desired, use an European locale such as Swedish.