FireFox 58 Update - Slow loading and startup

[BigJohnnyCool]

I am reporting that my copy of FireFox's Update 58 is causing slowness on my computer as well. It's slow starting up, as well as when I load a new page, and opening one up in another tab.

I have checked the "prevent accessibility services" box to have it on, cleared my cookies and cache, and enabled and disabled my hardware acceleration, and still the program loads slowly for me. None of my plug-ins seems to be the problem since they didn't recently update, and my anti-virus software wasn't recently updated either.

Would anyone happen to know what the problem is? Is this sluggish loading new/temporary to this Update?

[LIMPET235]

Hi,
The slowness should not be happening when starting up or page loading.

Try running in Firefox "Safe Mode".
> http://kb.mozillazine.org/Safe_Mode
or... Help > Re-start with Addons disabled or hold down your Shift key as you click the Firefox short cut..
Do not check any boxes.
This is a fault finding mode.
NB: Be careful of the "Delete all bookmarks except for back-ups" option.

Don't add any extensions or themes until it's working O.K.
If Firefox is O.K. in Safe Mode then it's possibly an extension/theme...etc causing it.
Run Firefox in normal mode & disable them all. Re-start Firefox.
Enable each in turn, or by ½'s, re-starting Firefox each time, till the faulty extension is found.
Either update or un-install it.

See this incomplete list,
> http://kb.mozillazine.org/Problematic_extensions

When in Safe Mode...
* The status of plug-ins is not affected.
* Custom preferences are not affected.
* All extensions are disabled.
* The default theme is used, without a persona.
* userChrome.css and userContent.css are ignored.
* The JIT/Javascript compiler is disabled.
* The default toolbar layout is used.
* Hardware acceleration is disabled.