Let me preface this article with the following. This information is provided "as is" without warranty of any kind, either expressed or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.

You see, I don't have a Mac upon which I may personally test. I've worked with some others who have Macs using Office 2011 and IRM. They've told me the following steps reset the IRM component. I thought I'd share this in case it adds some value for you.

Steps to resetting the Mac IRM client.

  1. Delete the following folder:
    1. ~/Library/Application Support/Microsoft/Office/DRM
  2. Delete the following files:
    1. ~/Library/Preferences/ByHost/MicrosoftRegistrationDB*.plist 
    2. ~/Library/Preferences/com.microsoft.MicrosoftOfficeDRM.plist
  3. There may be login keychains that need clearing. On the clients to which I had access the following steps were taken.
  4. Open the Keychain Access application,  and remove the following login keychains:
    1. corprights*
    2. com.microsoft.ipc.h
    3. com.microsoft.ipc.k