NetScaler Gateway for MAC is not connecting correctly: Protocoll shows "AGAS: Failed to initialise ssl vpn plugin"

I'm using the Citrix Netscaler Gateway for Mac (Version 3.1.8 which is the newest for mac) and macOS High Sierra.

When I use the Gateway Plugin to connect to our gateway, it seems to work, because the the NetScaler starts and shows the popup "Connected to xyz".

But when I try to open a website of the connected vpn, it is not possible.

Now comes the important part - the connection log: cagplugin.log:

{16-12-17:15h50m32s}:1649:{INFO}:{AGAS/AGKEXTInterface:-[AGKEXTInterface sendIoctl:withData:] No IOCTL socket yet.}:
{16-12-17:15h50m32s}:1649:{WARNING}:{AGAS/AGKEXTInterface:-[AGKEXTInterface createCtlSocket] ioctl(to com.citrix.kernel.sslvpn.control) failed with error 2.}:
{16-12-17:15h50m32s}:1649:{WARNING}:{AGAS/AGKEXTInterface:-[AGKEXTInterface createIoctlSocket] ioctl(ioctl_info.com.citrix.kernel.sslvpn) failed with error 2.}:
{16-12-17:15h50m32s}:1649:{WARNING}:{AGAS/Failed to initialize sslvpnPlugin}:
{16-12-17:15h50m32s}:1649:{INFO}:{AGAS/AGKEXTInterface:-[AGKEXTInterface sendIoctl:withData:] No IOCTL socket yet.}:
{16-12-17:15h50m32s}:1782:{INFO}:{Proxy Service Ready <AGEEProxyService: 0x6040000b57e0>.}:
{16-12-17:15h50m32s}:1649:{INFO}:{AGAS/Packet Filter Service Ready.}:
{16-12-17:15h50m32s}:1782:{INFO}:{Client version: 390}:
{16-12-17:15h50m32s}:1649:{INFO}:{AGAS/Capturing ARP on device en0}:
{16-12-17:15h50m32s}:1782:{INFO}:{Server version: 11.0.63.16}:
{16-12-17:15h50m32s}:1782:{INFO}:{Connected successfully to: gateway.mycompany.de}:

I think the important part of this is "AGAS/Failed to initialize sslvpnPlugin".

So it has something to do with an ssl vpn Plugin inside of NetScaler AGAS (which is AG AdminService) that could not be found or not be loaded.

Do you have any idea? I'm totally lost now.

Found the solution: In the mac OS high Sierra there is an extra security setting that blocks some applications for some reasons and that had blocked citrix.

You can find it in the Systems Settings -> Security. And there at the bottom of the window is a hint that shows that some software is blocked.

There is also a button to show the blocked software. You have to find citrix in the list and remove it. After that you have to restart mac.