Pages using dynamic JavaScript might fail to load in Firefox

Oct 29, 2019 13:16 GMT  ·  By

Mozilla rolled out Firefox 70 earlier this month, but by the looks of things, the update to this latest version isn’t exactly what users expected from the world’s second most-used browser worldwide.

The known issues section of Firefox 70 has recently been updated to indicate that websites with dynamic JavaScript might fail to load after installing the latest build of the browser.

The reason, Mozilla says, is likely tied to a storage component called Local Storage Next Generation, or LSNG, and which made its debut in Firefox 70.

So when updating Firefox to version 70, some websites might simply fail to load, although for the time being, it’s still not clear which devices are impacted and which aren’t.

“There is a known issue in Firefox 70 that prevents some pages or page elements using dynamic Javascript (like YouTube or Facebook) from loading properly,” Mozilla says, adding that a fix is already in the works.

No ETA is currently available as to when the fix could go live.

However, Mozilla provides users with an easy way to determine if their instance of Firefox is affected by the bug or not. What they need to do is visit this page and check the returned information to see if the storage system is working correctly.

Everything is working correctly with no bug whatsoever if you see the following message on the site:


Good. Totally Working. (fullyOperational)
On the other hand, if the bug exists on your device, this is the message that you should see:
Investigating. If this doesn’t go away, things are unexpected broken
And while a fix is currently in the works, Mozilla already has a workaround to help you to deal with the bug until Firefox is updated. The workaround, as pointed by TechDows, involves disabling a special flag in Firefox to remove the compatibility bug.

To do this, what you need to do is fire up Firefox and in the address bar, type the following command:


about:config
Next, you need to search for the following flag using the box at the top (make sure you copy and paste the code below to avoid any typos):
dom.storage.next_gen
Because LSNG comes enabled by default in the latest stable version of Firefox, this flag should be set to true in the browser. So double-click the flag to change it to false. Reboot the browser and then everything should be back to normal.

As explained in this discussion on Bugzilla, the error breaks down either full websites or only part of the contents on a page. The original bug report provides more detail on this behavior:

“Website banners are displayed but content fails to load correctly and just shows a blank portion of the page where the detail should be. For example, Facebook shows the top bar but doesn't not [sic] display any feed content. All of these websites should show data as they did before the Firefox upgrade.”

For the time being, it’s not yet clear when Mozilla is projected to release the fix for this bug, but the company says the developing team is already working on it. Most likely, the patch should make its way to the Nightly builds in the coming days, and it really shouldn’t take too long before this workaround is no longer required. The bug also appears to be happening in Firefox 71 beta, so presumably Mozilla will fix it in all versions of the browsers in the coming days.