the stuttering new Firefox 54

[Crow23]

http://ktla.com/2017/06/21/apparent-roa ... one-video/

The above is a video that plays perfectly on latest google chrome browser.
It also played perfectly with the last version of Firefox.
With Firefox 54 on my laptop, it is a stuttering freezing mess.
It's a very nice and late model laptop with i5 CPU and 16 GB RAM.

[Grumpus]

Probably because of the unnecessary links, beacons and trackers the dopey page tries to load.
It's a mess.

[dfoulkes]

I use a 12 year old laptop with one 4gig... Win7pro. I just played that vid in my test profile which uses u-block origin ... it played fine... no issues at all..

I suggest that you try some of this stuff for testing...then let us know.

Try running Firefox in safe-mode... NOTE: This is a testing procedure only ... NOT for normal browsing.
-- On the menu bar, click the Help menu and select Restart with Add-ons Disabled....
Firefox will start up with the Firefox Safe Mode dialog. Click continue in Safe Mode and don't check any items.

Note: You can also start Firefox in Safe Mode by holding down the shift key while Single/Double clicking on the icon.
* (option key while starting Firefox on Mac).
-----------------------------------------------------------------------------------------
>What safe-mode does ..... Safe Mode temporarily affects the following:
* All extensions are disabled. --- * The userChrome.css and userContent.css files are ignored.
* The default theme is used, without a persona. --- * The default toolbar layout is used.
* The Just-in-time (JIT) JavaScript compiler is disabled. --- * Hardware acceleration is disabled.

-- Safe Mode has no effect on the following --
* The status of plugins is not affected.
* Custom preferences are not affected.

This is the link to the main KB article for Safe-Mode ... but, use the above info 1st...
Safe Mode - MozillaZine Knowledge Base

Creating a new Firefox profile on Windows - MozillaZine Knowledge Base
And,.... DON'T TOUCH THAT "Choose Folder..." BUTTON! ... unless you fully know all about it.

From a prior post from Dan Raisch (with minor changes) ...

(If using a version below Firefox 3.5.) Clear the browser cache (Tools->Clear Recent History->select cache->click on "Clear Now" button).

Else... use menu path Tools->Options->Advanced->Network tab->click on "Clear Now" button.)

Delete any cookies relating to the site(s) involved (Tools->Options->Privacy->Show Cookies button).

Note: The above is for Windows so if you're using a different OS refer to this...
http://kb.mozillazine.org/Menu_differen ... x,_and_Mac

[hch]

I have a six year old Toshiba laptop using uBlock Origin. No problems here.

[Grumpus]

Just a note - the page tries to load a player which may be conflicting with the OPs new Firefox media setup.
Age of the system has little to do with it if the players used are compatible or recognized and the connection speed is not interfered with other things trying to load.