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Hello all,

We’re currently experiencing a very perplexing issue to do with the EE manager, whereby it appears that the JavaScript files powering things like drop-down menus, ajax filtering, RTE implementation etc. aren’t loading correctly.

Our difficulties arose after migration to a new host, and the complicating issue is that the problem appears to be intermittent, and is affecting some users more than others. Basically for short periods of a few minutes, everything loads and works as expected, then a while later a page load will stall, and the browser console reports ‘Network connection lost’ on one of the index.php requests that appears to point to javascript files (notably the jQuery UI library) - I’m not 100% certain of this but it certainly seems to be the case. We don’t experience any problems loading Manager icons, graphics, css etc (back end looks fine until you try to click something). This behaviour will then persist for up to an hour when afterwards things will begin to work normally again for short time, and so on.

One of our team reports that from his home he is able to use the system without any problems, and indeed if load the site via iPad using 3G, I can also use it unhindered, whereas two different machines here in the office cannot. Two other Editors working from various locations (one in France) experience the problems consistently. We’re therefore suspecting some kind of DNS or network-related problem, but can’t fathom why it would be related to JavaScript only.

Our web hosts have been unable to find an issue. The problem is present in various different browsers. The front-end of the site loads flawlessly.

We’ve re-uploaded, re-installed and upgraded to the latest version of EE, to no avail.

Getting a bit desperate here so any suggestions would be greatly appreciated!

Many thanks in advance

I’ve had multiple problems when using an add-on, or third party javascript widget using a different version of jQuery than that in the CP. EE loads jQuery 1.7.2 for use in the CP. If you have a widget on the frontend calling a different version, or a custom version of the same 1.7.2, then you can get collisions that have unpredictable behavior. Worth looking into.

Enquire with your new hosting provider is using either mod_security, or mod_evasive. We run a hosting platform built specifically for high performance ExpressionEngine hosting and we run a very secured set-up with both mod_security and mod_evasive and we had to put a bunch of effort, especially with mod_evasive to stop it from incorrectly blocking backend admin resources.

So in brief, it’ll be almost certainty your hosting provider tripping up and randomly blocking resources. The fact you mention that after an hour it resets, I’m almost certain mod_evasive is in play here.

Hi Michael, thanks for this, it would make total sense if this were the case. I’ll check with them and post findings here.

@wildrock - thanks for your suggestion, pretty sure this isn’t the case though as all was working ok on the previous host, and I don’t think the intermittent nature of the problem could be explained by this. But will check this too.

Ok, host reports that neither mod_security or mod_evasive are in place. It’s a Cloud server so has load-balancing at work, but that’s it, apparently.

Haven’t been able to find a conflicting jQuery load either, but will keep looking.

Meanwhile any further ideas gratefully received…