Make the error useful, and save the support call

Another code review comment, this time this is an error message being raised:

The comment I made here is that this error message lacks a very important detail. How do I fix this? In this case, the maximum number of connections is controlled by a configuration setting, so telling that to the user as well as what is the actual configuration entry to use is paramount.

If we give them all the information, we save the support call that would follow. If the user don’t read the error message, the support engineer likely would, and be able to close the ticket within moment.