Windows 10: Store login shows only a grey box

[German]Some Windows 10 users are facing issued, if they trying to sign in to the Windows store (and/or other app). Only a grey box pops up and disappears after few seconds. Here are a few hints to solve that issue.

I came across this issue within a German Microsoft Answers forum thread. But searching the web, I was aware, that many users are facing this store login issue (here, here, here, here for instance)

The error in detail

When trying to log in to the store, a grey box appears for  few seconds and then disappears. Some users posted a screenshot of this behavior. Below is a screenshot I've obtained from my German Windows 10, so the error message in foreground is still in German.

Users are facing a grey box during log in to Windows store using a Microsoft account. The popup box disappears after 10-15 seconds. In some cases, the following error message will be shown:

"We encountered an error. Please try signing in again later."

I've tested this behavior also with Windows 10 Creators Update and received error 0x800706D9  (EPT_S_NOT_REGISTERED), or error 0x80070426 (ERROR_SERVICE_NOT_ACTIVE).

Fix #1: Check services

If the Windows store login hangs, a missing service may be the root cause. Login to a Microsoft account is handed over in Windows 10 to to Microsoft Account Sign-in Assistant service.

1.Type settings  in taskbars search box, right click to Services and select context menu Run as administrator.

2. Search entry Microsoft Account Sign-in Assistant and double click this entry for wlidsvc.

3. Check on the General tab, whether the service start type is set to 'Manual' and the service can be launched.

I've set the start type to 'Deactivated' in the screenshot above and I stopped the service, to provoke the grey box login error within my test environment. I also found this hint within this US MS Answers forum thread.

BTW: A missing Microsoft Account Sign-in Assistant service could also be the reason, why some users are suddenly failing to login to a  Microsoft account..

Fix #2: Check Windows Credentials

If the service runs, some corrupted Windows login credentials may be the root cause for login issue. I came across this hint within this German Microsoft Answers forum thead.

1. Launch Settings app via start menu and type 'logo' into the Windows Settings search box.

2. Select Manage Windows Credentials in the pull down menu and inspect the entries in the Windows Credential window show below.

Delete all entries related to your Microsoft account under "Generic Credentials", and if available also "Other elements" like SSO_POP_User and SSO_POP_Device. Click the button on the right margin and select the Delete hyperlink.

What else can we do?

If the two fixes given above doesn't help, you can try a few additional tests and diagnose steps.

• If you are using VPN software, uninstall this program and test, if the issue is solved.
• Use Internet settings and check, if a proxy server is configured. Remove the proxy server from settings.
• Rest Internet Explorer using the Advanced tab in Internet Options.
• Create a new user account and try if store login is possible with your Microsoft Account.
• Also try to create a new Microsoft account and test if that account works.

And you can do a system check using the instructions given here: Check and repair Windows system files and component store.

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