Hi Wensonwang,
what about your internet connection?
Are you working on a single workstation?
are you changing the network connection or machine frequently?
If you go to your OctaneLive page , you can check where is your license and if is active or not.
ciao beppe

Yes I am working on a single ...

I always have to activate my account when I open cinema4D.
Sometimes it works but most of time it will tell me that Could not connect to SSO server.
Octane V3
WIN 10
GTX980TI

I have the same problem as you.