I want to upgrade my CallManager to 3.3(5)sr2c for eventually updgrade to 4.2 but when I download and run the Upgrade Utility it's found an error with the Software version validation.
The error is
OS service release has incorrect version (expected "2000.2.6sr5", but found "none")
So I want to get this update but I didn't find anywhere on the cisco website or microsoft website.
Does somebody knows where can I download it.