NFA SPDY Inadequate Transport Security error

Document ID : KB000129497
Last Modified Date : 14/03/2019
Show Technical Document Details
Issue:
With SSL enabled, IE is able to access https://nfa_host, but Chrome or FireFox errors out with a ERR_SPDY_INADEQUATE_TRANSPORT_SECURITY.
Resolution:

Disable HTTP/2 in IIS on Windows Server 2016

If you decide to disable HTTP/2 in IIS on Windows Server 2016 and only use HTTP/1.1, you can do so by adding two DWORD registry keys. You can copy the text in the box below into an empty Notepad file and save it as a .reg file. Then double-click the file to import the registry keys and reboot.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HTTP\Parameters]
“EnableHttp2Tls”=dword:00000000
“EnableHttp2Cleartext”=dword:00000000

 

If you decide to enable HTTP/2 at a later time, you can either delete the two registry keys or change their values to 1.

 

How to Disable HTTP/2 in Firefox

If you’re trying to browse to a website and you’re getting the error NS_ERROR_NET_INADEQUATE_SECURITY in Firefox and you’re not an administrator of the server, you can disable HTTP/2 in Firefox.

  • Open Firefox and type about:config in the address bar
  • Click on I Accept The Risk
  • Search for network.http.spdy.enabled.http2
  • Change the value to False
  • Restart your browser