This problem may arise if you are using a proxy server on your network or using Socks 4 & 5 network.
"Case-specific options" permits attorneys to add cases for which they are not counsel of record but in which they would like to receive notices of electronic filing.
It permits attorneys to remove any such cases when they no longer wish to receive notices.
That is probably why my recent Windows 10 update worked fine on one but did not "take" properly on my wife's machine, which went into endlessly rebooting.
CM/ECF users must log in to CM/ECF and update their account whenever this information changes.
This problem may also arise if you or your ISP is using Firewall.