[Request product key despite valid key code.]

Hi

I downloaded the Affinity Photo from my university to do some figures for my research. The program worked fine until a few weeks ago when it prompted me with the message that the product key was invalid although the keycode from the university states 1 year activation and it is less than 6 months since I installed it. I got it working again by providing the key once more but the next time I was to use the program I got the same message and could not open my file, the key code is now invalid. Since I had installed Affinity Publisher also, I did a workaround by using it instead to be able to view my files but now Affinity Publisher seems to be doing the same thing... Since the product key is a generic one provided by the university it should be working...