This is an incedent that a customer reported me, the problem was that he has a number of Mac devices that were not able to connect to the S4B OnPremise installation, each time they tried to connect to the client, the received an error.
So, we started to troubleshoot the problem, we revised the logs and then we realized that in one of the trace logs, there was a message related with the certificate, so probably the error was in that direction.
How it was a Mac device, it was not possible to add the device to the domain, so the domain certificates were not included in the chain certificate root, and for that reason the devices does not trust the discovery url from the S4B. So, we donwloaded the certificate from the discovery url, and we installed the certificate in the chain root of each one of the Mac devices that the customer has.
Once it has been done, we were able to connect to S4B trhough the different devices. Could be a silly thing, but we get stuck into that problem for several days.
Hope that helps!