Getting "ERR_HTTP2_INADEQUATE_TRANSPORT_SECURITY" when trying to open the SMP Console in Chrome or Firefox
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Getting "ERR_HTTP2_INADEQUATE_TRANSPORT_SECURITY" when trying to open the SMP Console in Chrome or Firefox


Article ID: 260889


Updated On:


IT Management Suite Client Management Suite


The customer reported that when he tries to open the SMP Console in Chrome, Edge or Firefox, he gets the following error message:

This site can't be reached.

The webpage at might be temporarily down or it may have
moved permanently to a new web address.


If he tries the same on Internet Explorer, the SMP Console opens fine.


ITMS 8.5, 8.6, 8.7


There are actually multiple causes that might be responsible for the ‘ERR_HTTP2_INADEQUATE_TRANSPORT_SECURITY’ error.

What this error indicates is that there are compatibility issues with Chrome’s (and other browsers too) security protocols. One of the major causes of this error is that there’s no proper data flow with the revised network protocol, i.e., HTTP/2 on the Windows server and Chrome. Other reasons include browser cookies, corrupted cache files, bugs due to the outdated Chrome version, and such. 


The most common way to overcome this browser limitation is by disabling HTTPS/2 on Windows (While HTTP/2 is generally good for security purposes, it also demands way stricter requirements).

Disable HTTP2 and try it again to load the SMP Console on the previously affected browser (in this case, Chrome):

  1. Start → regeditEditor

  2. Navigate to the folder/path: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HTTP\Parameters

  3. Under the Parameters folder, right-click the white-space, and add 2 new DWORD (32-bit) values:

    • EnableHttp2Tls

    • EnableHttp2Cleartext

  4. Ensure both new values have been set to 0(disabled) by right-clicking the value and clicking "Modify..."

  5. Restart the OS.


As well you can check the following article for other suggestions:

How to Fix ERR_HTTP2_Inadequate_Transport_Security Error in Chrome (


How to avoid the ERR_HTTP2_Inadequate_Transport_Security error | ITIGIC