There may happen some cases when your Windows (Universal and Modern/Metro) Apps won’t work as you expect from them. In such cases, most of Windows support forums and blogs would suggest you to reinstall the defective apps. So you can either uninstall the apps manually and install them again from Store or you can simply re-register the apps as mentioned in this guide and go ahead:
In above mentioned tutorial, sometimes re-registering the app may fail due to different causes. When the process is failed, you may possibly came around a detailed error message written in red color. Here it is:
Add-AppxPackage : Deployment failed with HRESULT: 0x80073CF6, Package could not be registered. Merge Failure : error 0x80070003 : Cannot register the *PACKAGE NAME* because there was a merge failure with following file: *FILE NAME*.
*Here, the PACKAGE NAME and FILE NAME are variables. For example, the PACKAGE NAME may be like Microsoft.WindowsStore_2015.8.3.0_x86__8wekyb3d8bbwe for which the FILE NAME may be C:\Program Files\WindowsApps\Microsoft.WindowsStore_2015.8.3.0_neutral_split.scale-150_8wekyb3d8bbwe\resources.pri.
After getting this error, you need to check out the log created in Event Viewer for this process, which will tell you about the cause of this error. Generally, it is observed that this error may come into play if the registry key owner for corresponding entries to app package is set to wrong person. If the registry key owner would be set to SYSTEM (which is default), then we can easily prevent this error from happening.
So here are the simple steps you need to follow to avoid this issue:
FIX : Deployment Failed With HRESULT: 0x80073CF6, Package Could Not Be Registered. Merge Failure : Error 0x80070003 In Windows 10
Registry Disclaimer: The further steps will involve registry manipulation. Making mistakes while manipulating registry could affect your system adversely. So be careful while editing registry entries and create a System Restore point first.
1. Press + R and put regedit in Run dialog box to open Registry Editor (if you’re not familiar with Registry Editor, then click here). Click OK.
2. In the left pane of Registry Editor, navigate to following registry key:
HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\AppModel\Repository\Packages\*PACKAGE NAME*
*Substitute the same PACKAGE NAME, which you received with the error, for ex. Microsoft.WindowsStore_2015.8.3.0_x86__8wekyb3d8bbwe.
3. Now right click on the registry key for package and select Permissions. Click Advanced button in the property sheet (refer below screenshot).
4. Next, in the Advanced Security Settings window, verify the owner of the key. Since you’re facing this issue, the owner could be anything except SYSTEM. So we’ve to set the SYSTEM as owner and make it default. Click on Change link.
5. Then click Advanced in the Select User or Group window.
6. Moving on, in the below shown window, click Find Now. Then scroll down through Search Results and select SYSTEM. Click OK.
You should now see SYSTEM in Select User or Group window. Click OK.
7. Finally, you’ve set SYSTEM as the owner of registry key. Check Replace owner on subcontainers and objects and Replace all child object permission entries with inheritable permission entries from this object options. Click Apply followed by OK. Click OK in the property sheet as well. Close Registry Editor.
Now reboot the machine and re-try to re-register the app. It should work fine by now.