Do you have HSO? Or have you installed the demo version of HSO which comes with C6?
Once the demo runs out, you will get this licence error message and its a PAIN to get rid of. I actually ended up with an unusable Project because I couldn’t get past it. I had to trace all the components of HalionSonic (there is no uninstall option) and then re-install it.
[edt to add - this was with HalionSonic full version, not SE, but the problem may be the same]