Hello,
Sorry to hear you are having issues. Please post screenshots of what popup do you see? Also, look for any installed software that do periodically clean up. It might delete off the license signature file. This will make Start11 think you are not activated.

Thank you.
Basj,
Stardock Community Assistant.

Please try, uninstall Start11, reboot immediately (important), download latest version available in your account product download page: https://store.stardock.com/myaccount/products. Install it, reboot immediately again. Retest it and report back.

Thank you,

Basj,
Stardock Community Assistant

Upon reinstalling the latest version, do you get to activation dialog box? Also, perhaps into this: https://support.stardock.com/space/SHC/1419378826/The+Stardock+installer+failed.

Thank you,

Basj,
Stardock Community Assistant