[Solved] ADFS WAP Error The operation stopped due to an unknown general error. Error code 0x8007520c

This week I had a customer who couldn’t connect to Office 365 with Outlook, after a server reboot.

When they tried to connect to Office 365 online, there was an error from the ADFS server.

I Quickly realized the ADFS wasn’t working properly.

I then started the Remote Access Management Console, and there was this error:

The operation stopped due to an unknown general error. Error code 0x8007520c

Solution:

The operation stopped due to an unknown general error. Error code 0x8007520c

Checking the Web Application Proxy Server: The service is stopped

Trying to start the service resulted in an Error:

Windows Could not start the Web Application Proxy Service service on Local Computer.

Error 0x80190191: Unauthorized (401).

Every time I have problems with an ADFS server I first look into the certificates:

dir cert:\LocalMachine\my

I Reactivated the correct certificate:

<Thumbprint ID> => The Thumbprint ID from the certificate found earlier

STS.DOMAIN.COM => Your FQDN name for your ADFS server

Install-WebApplicationProxy –CertificateThumbprint <Thumbprint ID> –FederationServiceName STS.DOMAIN.COM

Enter credentials from the local administrator of this server

The certificate is reactivated

You can now start the Web Application Proxy Service service, and everybody is able to use Outlook, and login on Office 365 portal

You can test your ADFS :

https://STS.Domain.com/adfs/ls/IdpInitiatedSignon.aspx