1195128 - DOM Inspector 2.0.16

Status: RESOLVED DUPLICATE of bug 1078121

(Other Applications :: DOM Inspector, defect)

Description

[Chuck Baker]

DOM Inspector does not load/work in Fx 42.0a2 (2015-08-16).

Tools > Web Developer > DOM Inspector generates message in browser console:

TypeError: content is null browser.xul:1:1

Tried with a new, otherwise empty profile. Same results.

Comment 1

[Colby Russell :crussell (no longer Mozilla-ing)]

This is due to the multiprocess changes in Firefox that are enabled by default in 42.  No one is working on DOM Inspector as far as I know, so the only way to fix this is to turn off multiprocess mode from the preferences and then restart.

Comment 2

[Philip Chee]

(In reply to Colby Russell :crussell (no longer Mozilla-ing) from comment #1)
> This is due to the multiprocess changes in Firefox that are enabled by
> default in 42.  No one is working on DOM Inspector as far as I know, so the
> only way to fix this is to turn off multiprocess mode from the preferences
> and then restart.
Any hints on how to fix this?

Comment 3

[Colby Russell :crussell (no longer Mozilla-ing)]

No idea.  I had stopped focusing on Mozilla-related projects almost entirely even by the time I had written that comment.

Comment 4

[Philip Chee]

In Multiprocess Firefox the content is running in another process.

From: http://mxr.mozilla.org/comm-central/source/mozilla/devtools/server/actors/inspector.js?rev=cc2af13f040c#187

// When the user selects a node to inspect in e10s, the parent process
// has a CPOW that wraps the node being inspected.  It uses the
// message manager to send this node to the child, which stores the
// node in gInspectingNode. Then a findInspectingNode request is sent
// over the remote debugging protocol, and gInspectingNode is returned
// to the parent as a NodeFront.

Since this functionality is expected to be present in Firefox we could piggyback on the remote debugging protocol.