Hybrid Configuration wizard - No Valid Certificates Found

Recently I had a case where a customer wanted to add a second exchange server in HCW to host receive and send connectors for redundancy . 

The problem was that the server was in a different site and child domain than the "primary" exchange server which was already part of HCW. 

As shown in the screenshot after selecting which servers you need to host Receive/Send connectors you need to select the Transport Certificate which will be used when connecting to Office 365. 

At this point I had the error : No valid certificates found for our 1st exchange server . 

After checking the server I identified that this was not true . The server had a valid cert and of course if you tried to run HCW from that server the error was gone. 

So what is the problem in this case ? The problem is that HCW is trying to query the server with the hostname as shown in the screenshot not the FQDN . But as mentioned the HCW was run in a different domain than the domain that the server in question was installed to . That said the hostname was not resolved to a real IP address .

So to overcome the problem you need to either  : 

Add a record to your local DNS server with the server name and the server IP or 

Add a hostfile  to your exchange server which will point to the real IP of the server we are looking for like this : 

After that if you did not close the HCW you will see this instead of the initial error : 

I gave it about 30 mins with no result so I decided to make a coffee , and close and reopen HCW wizard after about 30 mins or so . This was the result : 

Boom , case closed. Cheers!