To get more details about the above warnings and error messages, you can check the log files from the HCW located at the following path.

C:Users<user>AppDataRoamingMicrosoftExchange Hybrid Configuration


PowerShell failed to invoke ‘New-AuthServer’: Cannot acquire auth metadata document from ‘https://accounts.accesscontrol.windows.net ………….


Trying to create it by myself and the on-premise Exchange Management Shell will result in the same error.

Configure OAuth authentication between Exchange and Exchange Online organizations
https://docs.microsoft.com/en-us/exchange/configure-oauth-authentication-between-exchange-and-exchange-online-organizations-exchange-2013-help



Solution:
In my case for each Mailbox Server the -InternetWebProxy value showed the URL from the OWA. No matter why but regarding https://docs.microsoft.com/en-us/answers/questions/55961/exchange-hybrid-oauth-unable-to-create-new-authser.html this will happen frequently with other strange values.

As the Mailbox Servers don’t use any outbound proxy, I removed the wrong values and now the wizard runs fine.




Links

HCW has completed, but was not able to perform the OAuth error when running Hybrid Configuration
https://docs.microsoft.com/en-us/exchange/troubleshoot/hybrid-configuration-wizard-errors/hcw-has-completed-but-was-not-able-to-perform-oauth

Set-ExchangeServer –InternetWebProxy
https://docs.microsoft.com/en-us/powershell/module/exchange/set-exchangeserver

The InternetWebProxy parameter specifies the web proxy server that the Exchange server uses to reach the internet. A valid value for this parameter is the URL of the web proxy server.

In Exchange 2016 or later, to configure a list of servers that bypass the web proxy server and connect to the internet directly, use the InternetWebProxyBypassList parameter.

Exchange Hybrid – OAuth – unable to create New-AuthServer
https://docs.microsoft.com/en-us/answers/questions/55961/exchange-hybrid-oauth-unable-to-create-new-authser.html







HCW8110 – Encountered erros while running organization configuration transfer


START New-RemoteDomain -Name Standard -DomainName ‘*’
The remote domain * already exists

Reason and Solution:

Because the first Exchange Server in the organization was installed in german language, I am not responsible for that and was before my time, the default remote domain on-premise was named as Standard and not Default.

So OCT wants to create this remote domain with the New-RemoteDomain CMDlet in Exchange Online, but fail as there are still a default remote domain with the DomainName wildcard *

But why does the wizard not come up with following dialog in order to ask me if I want to overwrite them?




I presume the OCW only compares the names of the remote domains instead also the DomainName value located in on-premise and online regarding the warning above in the screenshots

There are some objects with the same name ….

and just when he tries to create the domain, Exchange Online detects that it already have an default remote domain with the DomainName value * as wildcard.

So I changed the Name value from Standard to default

Set-RemoteDomain -Identity Standard -Name “Default”


Now when I run the wizard and OCT, it will detect that there are the same remote domain objects and asks me to overwrite them or not.






Links


Hybrid Configuration Wizard errors when running the Organization Configuration transfer feature
https://docs.microsoft.com/en-us/exchange/troubleshoot/administration/hybrid-configuration-wizard-errors-organization-configuration-transfer

Hybrid Organization Configuration Transfer (OCT)
https://www.msxfaq.de/cloud/exchangeonline/organization_configuration_transfer.htm