1373239 - Responsive Design Mode doesn't show devices after update to 55 Beta 1

Status: RESOLVED DUPLICATE of bug 1373223

(DevTools :: Responsive Design Mode, defect)

Description

[bart-jan]

Attachment: responsive-design-mode.jpg

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:55.0) Gecko/20100101 Firefox/55.0
Build ID: 20170612224034

Steps to reproduce:

Firefox Developer just updated to 55.0 Beta 1.
Then I opened the Responsive Design Mode.


Actual results:

Responsive Design Mode opened and it looks like older (normal) Firefox versions. Meaning that I can't choose between different devices and the responsive design mode is not centered on the page, but is on the left-hand side of the browser.




Expected results:

I expected the responsive design to be in the center of the page and I expected to be able to select a device like iPhone SE or Nexus 5 as described on the page about the responsive design mode:
https://developer.mozilla.org/en-US/docs/Tools/Responsive_Design_Mode

Comment 1

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

Hmm, interesting.  The new RDM you are looking for is only available when multi-process Firefox (e10s) is enabled.  Starting in 55, a notification bar was intended to appear when old RDM opens (bug 1345515) to clarify this, but I am getting the impression that it did not.

Did anything like a notification bar appear when you opened RDM in 55 to explain this?

As for the issue you are reporting, can you check what about:support says in the "Multiprocess Windows" field?

Comment 2

[bart-jan]

I don't know about the multi-process Firefox. 
It worked before, after the update it didn't.

I didn't see a notification bar.

in about:support it says: "0/1 (Disabled by add-ons)" 
So I removed the few addons I had, but that didn't help.

Then I clicked the 'Refresh Firefox' button after that it dit work.
Reinstalled the plugins and everything worked...

Comment 3

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

Thanks for filing!  It sounds like this issue is the same as bug 1373223, so I'll mark this as a duplicate.

Please reopen if it ends up being a separate issue.