SharePoint Designer 2013 and Office 365 SharePoint Online. You may need that tool to create Workflows or change design of classic pages and much more. With more and better security features, it may happen that you run into the following scenario. Please be sure that you updated through WindowsUpdate everything!
Windows Server 2012, Windows 10 etc. plus SharePoint Designer 2013 installed. You may also have Office 2013 or Office 2016 installed and the issue may not occur in ex. WinWord 2016 when opening a document out of a library hosted on your SharePoint Online tenant. I would also say that this issue could occur when working with on-premise SharePoint and really modern authentication.
You want to open the site https://contoso.sharepoint.de
The following sign-in dialog may appear.
So far so good, but when you enter the password in the next dialog and the dialog comes back with the following screen, you may have this issue:
Text: There is a problem with your account. Please try again later.
Office 2013, the common part where SharePoint Designer 2013 is a member of, is not configured to use ADAL. You may find the ADAL.DLL (current build 1.0.2019.909) in the folder C:\Program Files (x86)\Common Files\Microsoft Shared\OFFICE15\ (or similar depending on 32bit or 64bit Windows/SPD2103), but that DLL will not be loaded when you take a look using ProcessExplorer.
Based on: Enable Modern Authentication for Office 2013 on Windows devices
You may add the registry key “EnableADAL = 1” and check also the key “Version”, it was there in my case, but you need that one as well.
After you changed the regkeys, restart SharePoint Designer 2013 and the sign-in screen should look like the following. You will still get two screens, only the last one looks different!
This issue occurred with tests in the Microsoft Cloud Germany (MCG) or also called Microsoft Cloud Deutschland (MCD).