Unable to accept request to unknown address

I had faced this error during TFIM IDP and SP partner communication.

Error:-
                                                         
Unable to accept request to unknown address, https://login.hostname.local:
9443/sps/idplogin/saml20/Login, this may be due to:                    
No configured endpoint or protocol exists that is mapped to this      
endpoint                                                              
Because this endpoint is unknown to this SPS, please validate that    
other applications such as the point of contact or partner sign-on    
servers are correctly configured for the correct endpoints.This is not
a problem with the SPS.      

Solution:- I found the solution that Service partner configuration mapped wrong.
                  vendor has configured wrong IDP URL in service provider configuration setting.
request failing because letter change in the URL  
with "Login", starting with a capital "L" and it has to be small letter.                          
                                                                       
https://login.hostname.local:9443/sps/idplogin/saml20/Login            
                                                                       
the call has to be made using login in all lower case... i.e.:        
                                                                       
https://login.athene.local:9443/sps/idplogin/saml20/login            

hope this helps.