SVN Exception: E230001: Server SSL certificate untrusted

When attempting to connection with the Subversion extension, I am receiving this error. How can I fix this?

Are you using the embedded/built-in SVN client, or are you pointing at your own svn.exe, and if so, what version is it? That behavior seems odd since BuildMaster explicitly instructs the command line client to ignore these types of errors: https://github.com/Inedo/bmx-subversion/blob/master/Subversion15Provider.cs#L318

As a workaround, I suppose you could run the command line under the same account that BuildMaster runs as and accept the certificate manually as you have likely done with your own account. If you need to accept the certificate as LOCAL SYSTEM, you can follow the steps here under Using LOCALSYSTEM Windows Service to accept it as LOCAL SYSTEM.

It's also worth noting that for the non-interactive/trust-server-cert flags to be acknowledged, the hostname of the SSL certificate installed on the server must be the same as the one in the repo URL. Is it possible that your SVN server cert is assigned to an IP address instead of the hostname, or vice-versa perhaps?