"The schema name attribute is not unique" error when you try to import an option set into Microsoft Dynamics CRM 2011

Symptoms

Assume that you apply Update Rollup 4 for Microsoft Dynamics CRM 2011. When you try to import a solution that contains an option set from an earlier version of Microsoft Dynamics CRM into Microsoft Dynamics CRM 2011, you receive the following error message:

Cause

After you apply Update Rollup 4 for Microsoft Dynamics CRM 2011, the Microsoft Dynamics CRM platform checks whether an attribute exists in an existing attribute list. To do this, the Microsoft Dynamics CRM platform searches for a lowercase key that uses the attribute name. However, if the attribute in the list uses a key that is not lowercase, the platform cannot find the attribute and tries to create the attribute. In this situation, the option set service discovers that the schema name of the attribute already exists and throws the exception.

Resolution

This issue is resolved in Update Rollup 7 and later update rollups for Microsoft Dynamics CRM 2011.  For more information about the latest cumulative update rollup for Microsoft Dynamics CRM 2011, click the following article number to view the article in the Microsoft Knowledge Base:

2795627 Update Rollup 12 for Microsoft Dynamics CRM 2011 is available After you apply the update rollup, follow these steps to override the default behavior of Microsoft Dynamics CRM 2011:

1. Download and extract the OrgDBOrgSettings tool for Microsoft Dynamics CRM 2011. The tool is updated when each update rollup is released and is included in the following update rollup:
   

   2795627 Update Rollup 12 for Microsoft Dynamics CRM 2011 is available

2. After you extract the tool, follow all the steps in the following Microsoft Knowledge Base article:
   

   2691237 OrgDBOrgSettings Tool for Microsoft Dynamics CRM 2011

3. Run the following command:
   

   Microsoft.Crm.SE.OrgDBOrgSettingsTool.exe Update /u <UniqueOrgName> LookupNameMatchesDuringImport TrueNote In this command, UniqueOrgName is a placeholder for the unique name of an organization. When you run the command, replace the placeholder and angle brackets (<>).

4. Perform an Internet Information Services (IIS) reset on all Microsoft Dynamics CRM application servers.

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.