OWA Show Error "Rights management operation failed." in exchange server 2010

When they try to open an e-mail with outlook web access. They get the following error message "Rights management operation failed."

 

Solution:

1. Log on to the exchange server and open (as Administrator) the Exchange Management Shell (EMS) 

 
2. Run "Get-OWAVirtualDirectory | FL" and search for IRM; you'll probably see that it's enabled.

3. Run "Set-OWAVirtualDirectory -IRMEnabled $false"

 
or you could provide the name of the identity using the -Identity "<identity goes here>"

for example:


4.  reset IIS  and try OWA again.