Am not able to open Outlook 365 cloud

Question

Am not able to open Outlook 365 cloud

EF Bagsværdvej 67 A/S 20

Hi!
I am trying to log onto Microsoft 365 cloud to access Outlook.
I enter www.office.com
A web page opens saying "Welcome to Microsoft 365 Copilot"
After a short while a window pops up saying,
"Authentication Required

You must authenticate to access this resource. Select "Continue" to authenticate your account."

I click the button Continue.
A popup window shows for a short while, and then I am returned to the "Authentication Required" window with the same message. I have also experienced that this goes into a loop, where the popup window is shown very briefly, and then back to the authentication window, back to the popup window.

In short, I am not able to get any further. I have tried to reset the setup for Chrome, which I use, but to no avail. And I also experience the same in Microsoft Edge, so it doesn't seem to be a problem connecting to the browser I use.

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Answer 1

Diana Mariz 11,025 Independent Advisor

Hi,

To further isolate the issue, if you are going to sign in through: account.microsoft.com, can you sign in without any issue with authentication required?

If yes, then once you are on the Microsoft account page, click the waffle menu on the upper left side that one that looks like 3x3 dot/or look like dice > then select Outlook > then see if you can sign in the Outlook page successfully.

EF Bagsværdvej 67 A/S 20 Reputation points

2025-09-21T11:36:23.43+00:00

Thank you! Yes, I am able to sign in to Outlook this way, so now I have access after all. Does this perhaps mean that the old way, www.office.com, no longer works, so that one should use this other way instead? Because the issue still remains with www.office.com. The important thing is that I am in now, though, so I appreciate your help.

Kind regards,

Roy
Diana Mariz 11,025 Reputation points Independent Advisor

2025-09-21T11:50:33.7466667+00:00

I am glad to hear that you can sign in now successfully. Instead of office.com, can you try http://outlook.office.com/ then check if you sign in without the authentication error.
EF Bagsværdvej 67 A/S 20 Reputation points

2025-09-21T20:22:56.3166667+00:00

Thanks a lot. http://outlook.office.com/ works fine too, so I'll use that, since it is shorter.