In this post, you’ll learn about the error code “0x803F6108” that is returned while you are developing or testing Store-related operations in your Windows app
Windows Store Error Message
Below is the description of this Windows Store Error.
The in-app purchase could not be completed because the app license is missing information. This error can occur when you side-load your app. To resolve this issue, uninstall the app and then reinstall it from the Store to refresh the app license.