Microsoft discontinued support for Windows Phone 8.1 in 2017, when it stopped releasing OS updates.

Microsoft has now finally announced the closing date for its online app store. An updated Microsoft support document states that the Windows Phone Store for smartphones with Windows Phone 8.1 installed will close on December 16, 2019. As a result, after that date, users will no longer be able to download apps from the store and install them on their smartphones.

Also, it will be impossible to install new or reinstalled old applications. If you’re still using Windows Phone 8.1, it makes sense to upgrade your apps by December 16th. Or you can upgrade your smartphone to Windows 10 Mobile, if supported.