[SOLVED] New tabs take several seconds to connect and load

[MarkkuIT]

Hello everyone,

Windows 10 x64, i7-5930k, 16GB RAM, GTX980. I'm running crazy over this issue. I installed FF57 a couple of weeks ago, caught by the claims for performance and improvements given by e10s (which ended up being true). So far so good, had a very pleasant switch over from Chrome, but since a few days my browser started misbehaving: whenever I search for something or go to a website, being it from address bar or bookmarks toolbar, Firefox takes several seconds (2-8s) before actually connecting to the site and loading it. In the meanwhile, I sometimes see "Connecting example.com..." on the bottom. If I try opening multiple sites at the same time, they all behave the same and they all start loading at once when the issue is over. If I keep browsing after that, the issue seems to vanish and only comes back if I leave the browser idle for a while (sometimes a few minutes, sometimes 15+).

I tried disabling extensions, refreshing my profile, uninstalling + deleting all profiles and Mozilla folders & AppData manually + reinstalling, using safe mode, allow * in/out for Firefox in the firewall, disabling antivirus & firewall, tried both FF57 and FF58 (Nightly), uninstalling recently installed software, all to no success. I tried about:networking logging but no useful information seemed to come up in the log file, same goes for the firewall log. I'm truly out of ideas and desperate for help on this matter. I've noticed very few others reported this issue and were asked to try safe mode, but no further updates came in after that. I'm not experiencing this issue with any other browser on the same PC, and I'm also not experiencing it on another Linux computer with the same Firefox version.

Please help. Thank you.

[DanRaisch]

What security software is running on the Windows PC?

[MarkkuIT]

What security software is running on the Windows PC?

ESET Smart Security 10.1.219.0
Tried disabling firewall and, later on, disabled it completely, but nothing changed. Its firewall logs don't mention anything being blocked.

[DanRaisch]

Disabling a firewall may only disable the user interface but not stop the scanning/blocking functionality. You might try booting into Windows Safe Mode (with networking) to see if the problem exists when ESET is not loaded.
https://support.microsoft.com/en-us/hel ... -safe-mode

[therube]

When this happens, are other browsers (IE or whatever) also affected at that time?

[MarkkuIT]

Fixed!

The culprit was in the AV/firewall (NOD32). I disabled its services in safe mode, rebooted and the issue didn't show up. Enabling the services again made it come back. Ultimately I uninstalled it for another AV+FW solution and the issue is completely gone. So even though I had it disabled and with no blocking rules, NOD32 was still somehow interfering with Firefox (as suspicious as it is).

Thank you everyone for pointing me in the right direction!

[DanRaisch]

Thanks for reporting back to identify the source of the problem.