User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:52.0) Gecko/20100101 Firefox/52.0 Build ID: 20170323105023 Steps to reproduce: Updated from 52.0.2 to 53.0 Updated from 52.0.2 to 53.0.2 Actual results: reopening previous session the tabs of external sites remained hanging, for example www.repubblica.it and saw.cce.hp.com. internal sites are ok. Just reverting to version 52.0.2 problem disappears. Expected results: www.repubblica.it shoulda have displayed main page, saw.cce.hp.com should have displayed login page.
Geatano, can you please provide a log? See  on how to do it. IMPORTANT: Please add modules negotiateauth:5,NTLM:5 to MOZ_LOG. Thanks  https://developer.mozilla.org/en-US/docs/Mozilla/Debugging/HTTP_logging
No reaction from the reported, lack of data. Feel free to reopen when provided.