在 macOS 版本 10.15.3 下，可以在系统偏好设置下的安全设置中允许 Citrix Netscaler Gateway 使用的扩展，如此 serverfault answer中所建议的那样。
但是，macOS 10.15.4 不提供这种可能性，导致最新版本的 Netscaler Gateway 无法工作。
这可以在日志文件中看到。具体来说，在/var/log/cagplugin_install.log我可以看到：
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).
另外，在/var/log/cagplugin.log我可以看到这个：
{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.}:
结果是连接显然是成功的，但随后没有发生通信（发送零字节和接收零字节，如 Netscaler 网关状态窗口中所示）。
我使用 Citrix Netscaler Gateway 4.4.4和4.4.8进行了测试，结果相同。
有什么办法让它工作吗？