IRM Failed

Dear All,

I have setup a ADRMS successfully .

I have integrated with SharePoint 2010 and set up the permission as per below link.

http://office.microsoft.com/en-us/sharepoint-foundation-help/apply-information-rights-management-to-a-list-or-library-HA101790607.aspx

If Administrator tries to open the document from IRM enabled library means its opening fine, but when other users tries to open it throws following error,

The IRM protector for this file encountered an unexpected error. If the problem persists, contact your administrator.

Please advise us on this