Is the browser working as far as everything else?

We need to look at the sync logs.

Note: Do the following for each problem system/profile. And label each as to what system/profile.

Type about:sync-log<enter> in the address bar.

Open the last file created and Copy its contents Now Paste it into this forum.

If the file is too large;

Open a text/word program and load the file. Left-click once. Now <Control> A to highlight everything, then <Control> C to copy it.

Next, have your web browser go to; https://pastebin.com/

Paste <Control> P the content of the file in the window. Note: On the bottom, fill out the boxes as best you can.

Now press Create A New Paste. The page will reload. Copy the new web address, and post it here.

Note: Your System Details shows; User Agent: masking-agent

https://support.mozilla.org/en-US/kb/how-reset-default-user-agent-firefox

http://www.howtogeek.com/113439/how-to-change-your-browsers-user-agent-without-installing-any-extensions/

This is likely caused by a broken user agent that identifies you as Firefox/47.0, probably done by an extension.

• Mozilla/5.0 (masking-agent; rv:47.0) Gecko/20100101 Firefox/47.0

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Thanks for your replies, I restarted Firefox in Safe Mode with all extension disabled and the reconnect action still is working without finishing. Then I disabled hardware acceleration and tried reconnect again, the problem persists. This afternoon I will go through your replies again to see if I can try another remedy you recommended. I will report later.

I reset the items in the user agent section. That did the trick, my second PC now seems to synch.

Thanks very much for your help.