Cannot edit source after selecting View | Source (Cntl-U)

Question

After installing Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13, I cannot edit source text when I select "View" | "Source" (Cntl-U).
I can see the source, but I can't modify it. I believe I used to be able to do this on my prior Firefox release (can't remember exactly what the release number was, but it wasn't more than a couple years old.)

Answer 1

The built in option is a source viewer, not an editor. You can change this to use an external application.
You can do this by changing 2 hidden preferences.
# Type '''about:config''' into the location bar and press enter
# Accept the warning message that appears, you will be taken to a list of preferences
# In the filter box type view_source
# Double-click on '''view_source.editor.external''' to change its value to true
# Double-click on '''view_source.editor.path''' and set it to the path of the external editor that you want to use.
As an example, I use Notepad++ to as the source editor ([http://notepad-plus-plus.org/]), so I have set view_source.editor.path to C:\Program Files\Notepad++\notepad++.exe
You can use the Dafizilla ViewSourceWith add-on to select an external editor to view the source- https://addons.mozilla.org/firefox/addon/dafizilla-viewsourcewith/