The Windows Store is Microsoft’s marketplace for downloading apps. However, many times users may encounter one or the other problem in accessing and using the Store or the Apps. This post is related to resolving one such problem many users have very frequently encountered- that of a damaged Windows Store Cache. When you face issues when running Windows Store apps, the Windows Store Apps Troubleshooter is able to usually fix the problems. The troubleshooter scans your system to detect the problems that might be preventing it from working properly on your Windows 10. The troubleshooter then tries to solve the problem automatically without necessitating any action from your end. But what if the troubleshooter itself gives a message – Windows Store Cache may be damaged!?
If you receive a Windows Store Cache may be damaged error after running Windows Store Apps Troubleshooter, you may have to reset the Windows Store as well as the cache folder in the App Directory.
Windows Store Cache may be damaged
In the case of a damaged Windows Store Cache, the troubleshooter is helpful in just identifying the problem. Beyond that, it is not really of much use in resolving the issue. Thus, over here, the troubleshooter can only diagnose the problem, not treat it.
If you too have or are facing such a difficulty with your Windows Store, you might want to try to follow one of these two solutions to manually fix the problem.
Reset Windows Store
1] To reset the Windows Store cache, open the Sytem32 folder and look for the WSReset.exe. Right-click on it and select Run as administrator. 
The application will then reset the Windows Store without changing any of your settings or installed apps. Windows will automatically open the Windows Store upon the reset operation getting completed. You should now be able to access and use the Windows Store properly.
Reset the cache folder in App Directory
1] Open File Explorer, copy-paste the following path in the explorer address bar and hit Enter:
C:Users<username>AppDataLocalPackagesMicrosoft.WindowsStore_8wekyb3d8bbweLocalState
Again, in case your Windows is installed on some other drive, replace ‘C’ above with the system root drive, followed by the name of your own user account. Also, replace the text <username> with the username associated with your account.
2] Now, in the LocalState folder, check whether the cache folder is present or not. If it is there, rename it ‘cache.old’. After that, create a new folder and name it ‘cache’. In case the cache folder is not there by default, just create an empty new folder and name it ‘cache’.
Next, create a new folder and name it ‘cache’. In case the cache folder is not there by default, just create an empty new folder and name it ‘cache’.
3] Once you are done with the above step, close the File Explorer and reboot your system. After the reboot, run the Windows Store Apps troubleshooter again. This time it will not only detect the problem but also automatically resolve it.
Restart your system once more and try opening the Windows Store. This method should work even if you have a local account.
See this post if you receive a Service registration is missing or corrupt error message.