The following are a list of common issues based on the version of MacOS X/OS X/macOS if you have successfully connected to the bSecure Remote Access Service in the past but it no longer works. If you are connecting to the service for the fist time please see article KB0012498
Please note that Mac OS X older than 10.12 (macOS Sierra) no longer meets the UC Berkeley Minimum Security Standards and are not supported on the bSecure remote access service.
Mac OS X Yosemite and Older (10.10 and older)
Versions of Mac OS X 10.10 and older are not supported on the bSecure Remote Access Service. The client may install but connections will fail.
Mac OS X El Capitan (10.11)
El Capitan is no longer supported by Apple and is missing important updates to libraries needed to communicate with modern equipment. Users of El Capitan will have noticed that many web site have started appearing as Untrusted or with an invalid certificate. Users will have to manually update the certificate chain of trust. Information on how to perform this task can be found on the Internet.