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Invalid extension '<extension>' in AppMappings for folder '<folder>'

An extension listed in the AppMappings property of the specified folder is not a valid file extension. Multiple extensions must be separated by semicolons; it is not necessary to prefix an extension with a period.

To correct this error

  1. Double-click the error in the Task List to go to the referenced file type in the File Types Editor.
  2. In the Properties window, select the AppMappings property. Click the Ellipsis () button to open the Application Mappings dialog box.
  3. Select the mapping for the extension specified in the error message, and click the Edit button to open the Application Extension Mapping dialog box.
  4. Enter a valid file extension in the Extensions field. Extensions must be preceded by a period; multiple extensions should be separated by semicolons.

See Also

AppMappings Property | Application Extension Mapping Dialog Box