In Firefox 68+ you can only disable multi-process by creating an environment variable named MOZ_FORCE_DISABLE_E10S and set its value to 1. You can either use a .cmd file to start Firefox or set this variable in the Windows Control Panel -> System.

• https://techdows.com/2019/05/mozilla-firefox-68-doesnt-allow-turning-off-e10s.html

cor-el said

In Firefox 68+ you can only disable multi-process by creating an environment variable named MOZ_FORCE_DISABLE_E10S and set its value to 1. You can either use a .cmd file to start Firefox or set this variable in the Windows Control Panel -> System.

• https://techdows.com/2019/05/mozilla-firefox-68-doesnt-allow-turning-off-e10s.html

I'm not sure how to do either of those things, is there a tutorial on how to do that?

Felis-Licht said

I'm not sure how to do either of those things, is there a tutorial on how to do that?

Hello Felis-LIcht,

How to set environment variables : http://www.computerhope.com/issues/ch000549.htm

You can use the set command to create a temporary environment variable.

• open command prompt window
• change to installation directory
• type "set MOZ_FORCE_DISABLE_E10S=1" and press enter
• type "firefox.exe" and press enter

How to use set command : http://www.computerhope.com/sethlp.htm

McCoy said

Felis-Licht said

I'm not sure how to do either of those things, is there a tutorial on how to do that?

Hello Felis-LIcht,

How to set environment variables : http://www.computerhope.com/issues/ch000549.htm

You can use the set command to create a temporary environment variable.

• open command prompt window
• change to installation directory
• type "set MOZ_FORCE_DISABLE_E10S=1" and press enter
• type "firefox.exe" and press enter

How to use set command : http://www.computerhope.com/sethlp.htm

Thank you!

My pleasure - have a nice weekend !

McCoy said

Felis-Licht said

I'm not sure how to do either of those things, is there a tutorial on how to do that?

Hello Felis-LIcht,

How to set environment variables : http://www.computerhope.com/issues/ch000549.htm

You can use the set command to create a temporary environment variable.

• open command prompt window
• change to installation directory
• type "set MOZ_FORCE_DISABLE_E10S=1" and press enter
• type "firefox.exe" and press enter

How to use set command : http://www.computerhope.com/sethlp.htm

What installation directory? People who give directions like these seem to be techies who think everybody else is as well and on the same page. what does this mean please?

You can create an environment variable in the Windows Control Panel.

• Windows Control Panel -> System -> Advanced -> Environment variables

Otherwise you can start Firefox via a firefox-e10s.cmd file with this content:

set MOZ_FORCE_DISABLE_E10S=1

Add one of these depending on if you have a 64-bit or a 32-bit Firefox version (see "Help -> About Firefox" and the about:support page).

start "" "C:\Program Files\Mozilla Firefox\firefox.exe"
start "" "C:\Program Files (x86)\Mozilla Firefox\firefox.exe"

So firefox-e10s.cmd has two lines: a 'set' line and a 'start' line. You can use Notepad to create this file. You can create a desktop shortcut to use this firefox-e10s.cmd file to launch Firefox and disable multi-process.

Note that disabling this feature via a preference on the about:config page has been done for a reason as it breaks some features.

• https://www.ghacks.net/2019/05/17/going-forward-multi-process-cant-be-turned-off-anymore-in-firefox/
• https://techdows.com/2019/05/mozilla-firefox-68-doesnt-allow-turning-off-e10s.html

I got as far as the advanced tab. Now am I adding something in "user variable for Robert" or "system variable"?

Thanks.

I got as far as system variables in advanced under system properties, and added c:\program files\Mozilla firefox\firefox.exe after a semi-colon and adding to the "Path" line. I don't follow the rest of your description as to what I'm creating in notepad or where I'm putting such a file.

If you have set the environment variable in the "Windows Control Panel -> Advanced -> Environment variables" then you can start Firefox normally, no need to make further changes.

name: MOZ_FORCE_DISABLE_E10S
value: 1

I didn't put the name and value above. I added the C:\program files\mozilla firefox\firefox.exe on the Path line in system variables. Where does this go?

name: MOZ_FORCE_DISABLE_E10S value: 1

Never mind. Added "New" variable name and value as indicated. It worked finally. Thank you.

Hallelujah!!! I found this finally and found what I was doing wrong...I was doing the environment path as well...Now I've disabled E10s (Again) on all my systems and can once again launch EMAIL URLS and correctly open Firefox to the Website...Without the Environment Variable Edit it would just launch Firefox 68 to a Blank Page. This was the same as two years ago when they first Enabled E10s. I had disabled it at the time in ABOUT:CONFIG but when they disabled that ability several weeks ago it broke my ability to launch EMAIL CLIENT URLS correctly into Firefox 68. Now that I have E10s disabled once again I can click on URLS in my email client and launch into Firefox 68 correctly. I'm also only using about half as much memory and E10s wasn't doing anything to speed up browsing on my older systems but rather just using more memory.

motox22a said

Hallelujah!!! I found this finally and found what I was doing wrong...

Congrats! Navigating your way around these confusing support pages and finding the right answer or issue is often at least half the battle. Glad it worked out.