[German]Microsoft has just announced that they have fixed an issue with classic Outlook authentication in Microsoft 365. Here is some information.
Issues with classic Outlook authentication
ince the beginning of May 2020 there have been various problems with Exchange Online (see Online Service disruption (30.4. – 1.5.2020)). I didn’t follow it up, but in connection with the German blog post Microsoft Office Patchday (5. Mai 2020) I noticed the two comments here. Blog reader Tom wrote:
Since the latest update (Version 2004 Build 12730.20250) for Microsoft 365 we have the problem that Outlook constantly asks for the password, even if you save it (until now on three clients). Even deleting the credentials in the Control Panel under Windows Logon Credentials has not brought any improvement. Only uninstalling Office and reinstalling an older version (2004 Build 12730.20236) helped. Does anyone know this problem?
Blog reader Thorsten then pointed out, it’s an issue of Microsoft 365 failing to authenticate for Outlook:
I received a mail from Microsoft 365 Service Health an hour ago:
Title: Multiple credential prompts in the Outlook client
User Impact: Users may receive repeated credential prompts within the Outlook client.
This was on 6 May 2020 and probably concerned commercial cloud offerings. I noticed it because my wife complained that she hadn’t been able to access Outlook.com email on her iPad for ‘a few days’. But since there were the above comments about Outlook sign-in problems here on the blog as early as May 6, 2020, I didn’t do anything (even though the problem was related to the Outlook.com problems for home users). But I’m not completely sure if these problems were related to each other.
Microsoft deployed a fix
On May 7, 2020, Microsoft probably reacted to the problems with conventional authentication at Outlook.com. The following tweet from Microsoft with an announcement came to my attention.
We’re deploying a solution to address an issue in which users may be experiencing repeated credential prompts within the Outlook client when using Classic Authentication. Additional details can be found in the admin center under EX212047.
— Microsoft 365 Status (@MSFT365Status) May 7, 2020
The issue should been solved
Today I found a status message from Microsoft 365 on Twitter, where it was announced that the malfunction should now be fixed.
We’ve completed deployment of the fix and we’ve confirmed with multiple customers that the credential prompt issue has been resolved. Additional details can be found in the admin center under EX212047.
— Microsoft 365 Status (@MSFT365Status) May 11, 2020
My quick test with Outlook.com on iPad showed that there were no more sign-in problems. However, the test emails I sent to my Outlook.com account on Friday have not yet been delivered. On Twitter, a user suggested that Microsoft should also fix the problems with ‘modern authentication’.