Exchange HCW8078 - Migration Endpoint could not be created.

Recently during an implementation of the Hybrid Configuration Wizard I came across the HCW8078 error, this is now the 3rd time I've come across this so thought I'd make a note for everyone else.

This happens with EOL cannot talk to the MRS Proxy service and created the following errros in the HCW log file:

HCW8078 Migration Endpoint could not be created.
Error details: The HTTP request was forbidden with client authentication scheme 'Negotiate'. --> The remote server returned an error: (403) Forbidden.


Using the Test-MigrationServerAvailability command we can test access to the MRSProxy 

Test-MigrationServerAvailability -ExchangeRemoteMove -Autodiscover -EmailAddress user@domain.com -Credentials (Get-Credential)

As we can see this failed:

After checking that the:
MRS Proxy is enabled
Microsoft Remote Connectivity Analyzer https://testconnectivity.microsoft.com/
Authentication is configured correctlyOther checks - https://blogs.technet.microsoft.com/exovoice/2016/09/19/troubleshooting-issues-where-the-migration-endpoint-cannot-be-created-in-hybrid-scenarios/

Get-WebServicesVirtualDirectory|fl ExternalAuthenticationMethods,Externalurl,MRSproxyEnabled,Server 

I have found three times now that this can be resolved by disabling the MRSProxy, IISRESET, Enabling the MRSProxy and then IISRESET once more. Then the Test-MigrationServerAvailability command suceeds:

let me know if you had the same issue?