Pale Moon forum

I'm on 27.4.1 (64-bit), and since the last few updates (around 27.1.0) the browser exhibits massive layout issues when loading websites.

The problem exhibits itself in different ways:
1) The CSS doesn't load at all, and I'm served plain HTML (this is rare)
2) The CSS loads only partially
3) The CSS loads completely, but is messed up - usually images are swapped, as in Image A is in the place where Image B should be, Image C in place of Image D, and so on. (this is the prevalent case)

The thing is, the issue is not consistent, even on the same site. Sometimes, the issue goes away (i.e. the site renders correctly) after a single reload. Other times 2, 3 or more reloads are needed. Yet other times the site simply stays messed up. I had remained on the exact same hardware, and I have not been changing any settings or installing new add-ons between the Pale Moon updates. I also don't use any layout-changing add-ons. Running in safe-mode doesn't change a thing. 32 or 64-bit also doesn't matter.

I also decidedly remember I have never had such problems before. Curiously, now when I try older versions than 27.x.x., the problem now also appears.

For some sites, changing the compatibility mode helps, for others it doesn't. The issue's been manifesting across well-known big sites, and also small sites. Otherwise, the browser is fast, snappy and extremely stable.

Below I'm including a sample of three sites where the issues happen 99% of the time:
ninecommas.com - completely messed up formatting almost every time
boxofficemojo.com - instead of the site logo, the IMDbPro picture is shown
blitz-cinestar.hr - messed up every time, in different ways

Here is an imgur album of examples (the first image of the pair is the incorrect rendering, the second is the correct rendering): http://imgur.com/a/8BUoT

I'm really at a loss at what to do here... Any help?

More details needed, esp. any security/privacy add-ons/software and URLs: viewtopic.php?f=3&t=49

None of the sites mentioned display any issues when I visit them.
It's important to know what is between your browser and the internet. As satrow said: network security software may interfere. proxies may also interfere, even your router if it has some sort of web filtering enabled.

Hm, you're right. The only thing that did change on my system is the AV/firewall software. I switched from Avast free to Webroot right at the time the problems started! It just didn't occur to me look into Webroot, since on Vivaldi (which I have installed as an alternate browser) these problems aren't present. And right enough, when I disabled Webroot, the sites loaded normally.

After some fiddling around, it seems the culprit is the "Enable Web Filtering" setting, under the Firewall/Web Shield tab. It did something so Pale Moon wasn't loading sites properly, even though the process was greenlit in the Firewall settings. Switching web filtering to off, sites load normally. I'll investigate this some more with the Webroot customer support, and will report back if I find something in more detail.

In any case, a big 'thank you' for the assistance, guys!

The description of the problem reminds me of some old broken proxies that don't like http pipelining. Maybe their "web filtering" has similar problems by having a rather naive implementation of the http spec, expecting single, sequential requests only.

As a final update...

I posted on the Webroot community forum and opened a ticket with their customer support. A forum member reported using Pale Moon and not experiencing the same troubles I was having with the web filtering driver. Their CS first suggested doing a clean re-install (after collecting some logs that I had to sent them) without importing old settings, and that it should solve the issue. It didn't, though. After which they reported that the issue was PM being sort-of-Firefox, but not really - enough for the filtering driver to integrate with, but not enough to work properly.

Their solution: switch the filtering driver off.

I suspect there must be something else at play, too, if other Webroot users are not having the same issues with their PM instance. The only difference is that the forum member reported using PM portable (if i understood him correctly), while I use an installation.

Well, I didn't want to push the issue further, as I'm fine and things do work with this "solution".

You might want to check with the other Webroot Pale Moon users which User Agent they're using on your problem URLs.