[Microsoft Teams 4c7] Modern authentication failed here, but you'll still be able to sign in. Your status code is 4c7 error

Modern authentication failed here, but you'll still be able to sign in. Your status code is 4c7.

You may receive the above authentication error message when you are trying to login to your Microsoft Teams application from your corporate network with ADFS.

What is the cause of Microsoft Teams 4c7 error?

The reason for this issues is because Microsoft Teams requires Forms Authentication, when ADFS was deployed/setup the Forms Authentication wasn't enabled for the intranet usage (by default its disabled), it needs to be enabled explicitly.

Microsoft Teams 4c7 error

How to resolve of Microsoft Teams 4c7 error?

  1. Go to AD FS Microsoft Management Console
  2. Go to Navigation Pane -> Authentication Policies.
  3. Select Edit Global Primary Authentication from Actions in Details Pane.
  4. Now on the Intranet tab select Forms Authentication.
  5. Click OK and Apply changes.
Try Out Code2care Dev Tools:


Android Java Linux Microsoft Google Python macOS Notepad++ Microsoft Teams CSS PHP SharePoint Html Linux C Programs Bootstrap jQuery Sublime Android Studio Facebook Eclipse WhatsApp News MySQL Json HowTos JavaScript FTP S3


Code2care is an initiative to publish and share varied knowledge in programming and technical areas gathered during day-to-day learnings and development activities.

Students and Software Developers can leverage this portal to find solutions to their various queries without re-inventing the wheel by referring to our easy to understand posts. Technical posts might include Learnings, Tutorials, Trouble-Shooting steps, Video Tutorials, Code Snippets, How Tos, Blogs, Articles, etc.
πŸŽ‰ We are celebrating the 10th years of Code2care! Thank you for all your support! We hope we made a difference.
We strong support Gender Equality & Diversity.

We stand in solidarity with Ukraine - Make a donation to UNHCR - https://donate.unhcr.org/in/en-in/ukraine-emergency