If you receive Windows Store error message 0x803F7003 in Windows 10, while downloading, installing or updating Windows Store apps, the this post may help you. The error message you receive could be:

Try that again. Something went wrong. The error code is 0x803F7003, in case you need it.

To resolve this, you will have to clear or reset the Windows Store cache.

Open WinX Menu, select Run, type wsreset.exe in the box and hit enter to reset the Windows Store

cache.

Hope this helps.