Flexera InstallShield LE Serial Number not activating the software

[ngutortsenongo]

I have successfully downloaded Flexera Install Shield and installed it on my system, however the Activation of the product with the serial number sent to me is not going through.
Flexera InstallShield Limited Edition 2015. Activation offline is not going through. Please help what can I do to Activate it on my System?
The full Error message is below:
Offline Activation Failed
The offline transaction failed. Make sure that the response text is properly formatted. Click the help link below for more information.
Error 0 - Response is Corrupted.

[moore_con]

I am getting the same error. Did you ever get a solution/resolution? Or, did you just move on?