Sothink software, the registration has failed

Hi all,
When I try to activate the Sothink software, the registration has failed leaving an error message. Download and installation was smooth without any problem, but why I am facing this kind of error. Thinking of what might be cause? I checked the internet connection and it is working. Is any problem with Registration key? Help please.

Your product registration has failed. Error code 9. Please contact customer service!
