Separate Security Issue, please update your Flash 28.0 r0 by removing it with this tool : https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html If you use it Reinstall with Flash Player Version: 30.0.0.154 Current Version https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, . . . .) Note: Other software is offered in the download. <Windows Only>

Please do the following to fix registry and system files : 1)Use the Windows key + X keyboard shortcut to open the Power User menu and select Command Prompt (Admin). 2)Type Copy/Paste the following command and press Enter: 3)DISM /Online /Cleanup-Image /RestoreHealth 4)Reboot

Note : It is Microsoft Patch Tuesday today please update Windows 10 then reboot again or maybe the 1st one worked as it was ready to be rebooted.

Then try to Sync please.

What Extensions are you running please ? What Security Software are you running ?

• https://support.mozilla.org/en-US/kb/how-do-i-choose-what-types-information-sync-firefox
• https://support.mozilla.org/en-US/kb/firefox-sync-troubleshooting-and-tips

You can open about:sync-log via the location bar to see if there are recent error logs available. You can upload a recent log if the log is too big to put in a reply.

• https://pastebin.mozilla.org/

Pkshadow said

Separate Security Issue, please update your Flash 28.0 r0 by removing it with this tool : https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html If you use it Reinstall with Flash Player Version: 30.0.0.154 Current Version https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, . . . .) Note: Other software is offered in the download. <Windows Only> Please do the following to fix registry and system files : 1)Use the Windows key + X keyboard shortcut to open the Power User menu and select Command Prompt (Admin). 2)Type Copy/Paste the following command and press Enter: 3)DISM /Online /Cleanup-Image /RestoreHealth 4)Reboot Note : It is Microsoft Patch Tuesday today please update Windows 10 then reboot again or maybe the 1st one worked as it was ready to be rebooted. Then try to Sync please. What Extensions are you running please ? What Security Software are you running ?

• https://support.mozilla.org/en-US/kb/how-do-i-choose-what-types-information-sync-firefox
• https://support.mozilla.org/en-US/kb/firefox-sync-troubleshooting-and-tips

You can open about:sync-log via the location bar to see if there are recent error logs available. You can upload a recent log if the log is too big to put in a reply.

• https://pastebin.mozilla.org/

Thank you for the help!