I just installed and configured a new ADFS server. After the configuration I wanted to test out ADFS login using this address - https://sts.corp.viamonstra.com/adfs/ls/idpinitiatedsignon but it failed with this error:
The resources you are trying to access is not available.
Event log showed this error message
Quick configuration check with Get-ADFSProperties cmdlet and I discovered that by default it is not enabled.
Use the Set-AdfsProperties -EnableIdPInitiatedSignonPage $True command to enable the login.