Sorry to hear you are having issues.
We will need more info to help you .
1st , try a different browser or two incase one browser is blocking you /
2 nd. What version of Windows are you running
3 is your Stardock Account up to date
4 What apps do you want to buy ? you will need the right version for your version of Windows .
Report back here with this info then we can proceed with help, Thanks .
Stardock Community Assistant