Under macOS version 10.15.3, the extensions used by Citrix Netscaler Gateway could be allowed in the Security settings under System Preferences, as suggested in this serverfault answer.
However, macOS 10.15.4 does not offer such a possibility, making the latest version of Netscaler Gateway not work.
This can be seen in the log files. Specifically, in /var/log/cagplugin_install.log
I can see this:
2020-04-02 16:10:00 Install: Starting up Citrix Access Gateway client services.
/Library/Extensions/CitrixDNERegistry.kext failed to load - (libkern/kext) system policy prevents loading; check the system/kernel logs for errors or try kextutil(8).
2020-04-02 16:10:00 Install: /bin/launchctl load /Library/LaunchDaemons/com.citrix.daemon.dneregsvr.plist
2020-04-02 16:10:00 Install: Started dneregsvr.
/Library/Extensions/CitrixDNE.kext failed to load - (libkern/kext) system policy prevents loading; check the system/kernel logs for errors or try kextutil(8).
/Library/Extensions/CitrixSSLVpn.kext failed to load - (libkern/kext) system policy prevents loading; check the system/kernel logs for errors or try kextutil(8).
Also, in /var/log/cagplugin.log
I can see this:
{03-04-20:16h56m37s}:4084:{WARNING}:{AGAS/AGKEXTInterface:-[AGKEXTInterface createCtlSocket] ioctl(to com.citrix.kernel.sslvpn.control) failed with error 2.}:
{03-04-20:16h56m37s}:4084:{WARNING}:{AGAS/AGKEXTInterface:-[AGKEXTInterface createIoctlSocket] ioctl(ioctl_info.com.citrix.kernel.sslvpn) failed with error 2.}:
{03-04-20:16h56m37s}:4084:{WARNING}:{AGAS/Failed to initialize sslvpnPlugin}:
{03-04-20:16h56m37s}:4084:{INFO}:{AGAS/Packet Filter Service Ready.}:
{03-04-20:16h56m37s}:4084:{INFO}:{AGAS/AGKEXTInterface:-[AGKEXTInterface sendIoctl:withData:] No IOCTL socket yet.}:
The result is that the connection is apparently successful, but then no communication takes place (zero bytes sent and zero bytes received, as seen in the Netscaler Gateway status window).
I tested with Citrix Netscaler Gateway 4.4.4 and 4.4.8, with the same results.
Is there any way to make it work?