New
#11
I suppose the EFS encryption certificate and associated private key are outside of the user context where you try to access the WindowsApps folder, otherwise the files would be transparently decrypted as you access them, hence the job may be to find this certificate+key pair.
Running the certificate manager (MMC snap-in) as admin might help you find it, but I'm doubtful, otherwise it would have worked while you were trying as an admin. In the System user context, maybe... but all this post is just a wild guess.