Sorry to hear you are having trouble.
It seems that on every reboot (maybe not every reboot, but more often than not) I lose the activation - I have to re-activate it by entering my email address and password or licence key. I thought this affected just my main desktop PC, but I'm having the same issues (both the universal apps being empty and the lost activation) on both laptops and my other PC too. It seems weird that nobody else has reported this but it surely can't be just me if I'm having the same issue on all machines I have Start 10 installed on?
Press the Windows key and "R" at the same time. A "Run" dialog box will pop up, please paste the path below into the "Open" field and press OK.
In the folder that pops up, you should see a folder named Start10. Please delete this folder and all of its contents.
After you have deleted that folder, please attempt to activate once again and it should succeed without any errors.
Please let me know if this does not resolve the issue.
Stardock Support Manager