Windows - Deactivate HTTP/2 Protocol on Windows 10 and Windows 2016 Desktops

With some web browsers, you might encounter the error ERR_SPDY_PROTOCOL_ERROR when accessing a Windows 10 Horizon Agent Direct-Connection Plug-In (formerly View Agent Direct-Connection Plug-In) or Windows 2016 Horizon Agent Direct-Connection Plug-In desktop. You can prevent this error by deactivating the HTTP/2 protocol on the desktop.

Procedure

1. Start the Windows Registry Editor.
2. Navigate to the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HTTP\Parameters.
3. Add 2 new REG_DWORD values, EnableHttp2Tls and EnableHttp2Cleartext, to this registry key.
4. Set both values to 0.
5. Reboot the desktop.