ADFS external facing site error with 'Service Unavailable HTTP Error 503. The service is unavailable.'

Question

Hi All,
We have 2 AD FS (2016) servers, and 2 WAP servers (2016) and recently renewed SSL certificate for ADFS. During the same time, ADFS service account password expired and we updated that as well.
SSL renewal steps:
Installed the cert with private key on all servers (2x ADFS & 2x WAPs).
Re-established the trust between ADFS and WAPs. Operations Status on WAP: Web Application Proxy, AD FS Proxy, Web Application Proxy Core are all Green and status shows Working.
But when I try to log in to Office from external network, the AD FS signing page shows the below error. Am I missing something here?
Service Unavailable

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***HTTP Error 503. The service is unavailable.

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Any help would be appreciated!
TIA

Answer 1

If anyone is still having issues with this, I would check the following:

HTTP Error 503. The Service is unavailable

Cause #1: Invalid base address entered in the SAML login redirection page field.

Solution #1: Make sure your base addresses match your application and ADFS. For example, if ADFS was assigned https://sso.contosso.com/ your application should reflect the same address, https://sso.contosso.com/.

Cause #2: The ADFS services are not running.

Solution #2: Check your service account has up-to-date credentials and start or restart your ADFS services.

Cause #3: Not pointing to the correct resource endpoint, specifically /ls.

Solution#3: Make sure your address is also pointing to the correct resources, /adfs/ls.