SEP 12.1 RU2 Error 25010 Could not locate "Microsoft Test Root Authority"

Gents,

I'm encountering an issue when trying to install SEP 12.1 RU2. Below is a screen shot of the error message and here is the actual text.

Error 25010, Could not locate "Microsoft Test Root Authority" certificate in "Trusted Root Certification Authorities" store. It is required for this build of Symantec Endpoint Protection. Please install it and retry Symantec Endpoint Protection installation.

Now, the error message is pretty straight forward, but that certificate isn't installed on any other machines in which SEP installed correctly.

Any thoughts???

Thanks!!!