I have had this come up a couple of times, so far only with users that are trying to connect to our Horizon 6 environment from home. They'll select a pool to connect to, the connection will start, and they'll get a black screen followed by a Windows loading screen which resizes itself to fit their monitors, then the client will close out completely with a message saying "The connection to the remote computer ended".
Oddly, if I use my credentials to connect, I'll get the same behavior except that instead of the client completely closing out, only the session shuts down. The client stays open though and I can choose to connect to the pool again without logging back in. If I do this, it seems to reconnect me to the same session that I had just disconnected from because rather than showing me the Windows splash screen, it puts me into the desktop for a couple of seconds before killing the session again.
In the Horizon log on the client, I see this:
2016-01-08 17:20:43.141+-5:00 INFO (1C40) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ReconnectTicket CB
2016-01-08 17:20:48.071+-5:00 INFO (0B00) [WinCDK] PCoIPWindow::OnConnectionStateChanged : RemoteMKS connection failed with error 'The connection to the remote computer ended.'.
2016-01-08 17:20:48.081+-5:00 INFO (0B00) [WinCDK] AutoHideMessageBox::ShowAutoHideMessageBox : Show auto hide message:The connection to the remote computer ended..
2016-01-08 17:20:56.490+-5:00 INFO (0B00) [WinCDK] DesktopWindow::OnClose : [User] Enter CloseWindow.
2016-01-08 17:20:56.490+-5:00 INFO (0B00) [WinCDK] PCoIPWindow::PreDestroy : [User] Enter Pre-Destroy.
2016-01-08 17:20:56.490+-5:00 INFO (0B00) [WinCDK] PCoIPWindow::PreDestroy : [User] Exit Pre-Destroy.
2016-01-08 17:20:56.490+-5:00 INFO (0B00) [WinCDK] PCoIPWindow::OnDestroy : [User] Enter Destroy.
2016-01-08 17:20:56.490+-5:00 INFO (0B00) [WinCDK] PCoIPWindow::OnDestroy : [User] Exit Destroy.
2016-01-08 17:20:56.490+-5:00 INFO (0B00) [WinCDK] Services::DesktopClosed : The item closed is just the one that launched at last: 'cn=linkedclone-c1v9,ou=applications,dc=vdi,dc=vmware,dc=int'.
2016-01-08 17:20:56.490+-5:00 INFO (0B00) [WinCDK] Services::DesktopClosed : User has closed all windows, exiting the application, as it's not from URI or Horizon.
2016-01-08 17:20:56.490+-5:00 INFO (0B00) [WinCDK] Services::LogOffServer : [User] Enter Services::LogOffServer.
2016-01-08 17:20:56.490+-5:00 INFO (0B00) [libcdk] CdkUtil_SetLocalAddress: fd -1 < 0, not retrieving local address.
2016-01-08 17:20:56.506+-5:00 INFO (0B00) [WinCDK] Services::LogOffServer : [User] Exit Services::LogOffServer.
2016-01-08 17:20:56.506+-5:00 INFO (0B00) [WinCDK] DesktopWindow::OnClose : [User] Exit CloseWindow.
2016-01-08 17:20:56.506+-5:00 INFO (0B00) [WinCDK] USBDevices::~USBDevices : Release USB instance. The broker is 'PUBLIC_FQND_OF_SECURITYSERVER'. The desktop is 'LinkedClone-C1v9'.
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_Release: 00000000
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_ValidateHandle: 00000000 (bad magic)
2016-01-08 17:20:56.506+-5:00 ERROR (0B00) [WinCDK] USBDevices::FreeEnumData : CdkViewUsb failed to free enumeration. The reason is 'ViewUsbStatus_BadHandle'. The broker is 'PUBLIC_FQND_OF_SECURITYSERVER'. The desktop is 'LinkedClone-C1v9'.
2016-01-08 17:20:56.506+-5:00 INFO (0B00) [libcdk] CdkViewUsb_CloseDesktop: releasing USB devices for desktop "cn=linkedclone-c1v9,ou=applications,dc=vdi,dc=vmware,dc=int@7412"
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_Release: 03CB8640
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_ValidateHandle: 03CB8640 (DESKTOP, ref:1)
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_RemoveChannel: 03CB8640
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_ValidateHandle: 03CB8640 (DESKTOP, ref:0)
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: mmfw_PostMsg_Tracked
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_ValidateHandle: 03CB8640 (DESKTOP, ref:0)
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_DropAllConnectedDevices: desktop=03CB8640
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_Release: 03CC8370
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: ViewUsb_ValidateHandle: 03CC8370 (CLIENT, ref:2)
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: mmfw_PostMsg_Tracked
2016-01-08 17:20:56.506+-5:00 DEBUG (0B00) [vmware-view-usbd] CdkViewUsb_Log: ViewUsblib log: mmfw_PostMsg_Tracked
2016-01-08 17:20:56.506+-5:00 INFO (0B00) [libcdk] TaskCombiner: CdkDoLogoutTask(TODO) added, group task num:1, total task num:1.
2016-01-08 17:20:56.506+-5:00 WARN (0B00) [libcdk] CdkDebug_PrintErr: Error reading from tunnel HTTP socket: An existing connection was forcibly closed by the remote host.
I thought that the bold, red part up there might give some clue as to what's going on... any thoughts? This is not affecting all external folks (I can connect fine from my laptop as can at least 8 test users), and it doesn't seem to matter whether I use PCoIP or RDP, although RDP just closes with no pop up windows, so I think that we can rule out a firewall problem, but I'm open to suggestions. I get similar behavior when I try to connect with my iPad though, so that's probably relevant.