I got upgraded to Norton Security Standard Version 22.10.0.85 today which also upgraded my Norton Security Toolbar Version to 2017.11.0.1 as shown in Firefox 54.0.1. While the NSTB remains enabled, it is marked as incompatible with muliprocess by Firefox. Earlier, on 10-Jul-2017, NTSB 2017.9.2.2 was disabled by FF-54 due to this incompatibility, but after I reverted to NSTB Ver 2017.9.0.2 as per this thread https://community.norton.com/en/forums/firefox-5401-has-disabled-norton-toolbar-add-2017922-updated-10-jul-2017, I managed to get the older NSTB version enabled in FF, though still incompatible.
Thought this new upgrade of NSS & NSTB would have resolved the issue, but NSTB remains incompatible with Multiprocess in FF hence Multiprocess feature remains disabled in my FF. Is there anyway I can have this fixed permanently ?