Error: Sequence contains more than one matching element

The "Sequence contains more than one matching element" error indicates that the C:\inetpub\wwwroot\BCEnterprise\Languages folder on the Web server contains two or more language files with the same CultureCode property. The CultureCode property can be seen on the first sheet and second row of the language file. This error is shown only to users that have the language selected in their user preferences.

When the user clicks the Restart button in the error message, another error message is returned, which says "Failed to connect to server".

This problem can occur if the file was duplicated by the user, or if there was a problem during an upgrade.

Solution

Remove the duplicate language file, or edit the duplicate CultureCode property in the appropriate language file. Then reset the BCEnterprise application pool under the IIS.