#21 Reads chm in Firefox 3.6 but not Firefox 7

[John99]

THIS DOES WORK much as expected, and does read chm files from Firefox 3.6
The add-on can be installed, and runs in Firefox 7.0a2 but fails to read chm files.

__Details of problem.__
1) Install Firefox on Windows XP.
2) Force installation of this application CHM Reader add-on
( more than one way to do that, I installed another addon Compatability reporter, and downloaded and installed CHM from the Mozilla Add-on site; I could have manually installed by copying files from an active fx 3.6 profile & possibly modifying them)
3) Use CHM Reader,
using keyboard shortcut Ctrl + E to open * CHM Reader * sidebar --> Open CHM Files --> Browse
Select a suitable chm file on local disk, click *Open* This results in an error.

Error displayed
Alert /!\ Firefox doesn't know how to open this address, because protocol (chm) isn't associated with any program

Error found in Web Developer --> Error Console [ may use keyboard Ctrl + Shift + J ]
Error: uncaught exception: [Exception... "Component returned failure code: 0x804b0012 (NS_ERROR_UNKNOWN_PROTOCOL)
[nsIWebNavigation.loadURI]" nsresult: "0x804b0012 (NS_ERROR_UNKNOWN_PROTOCOL)" location: "JS frame ::
chrome://global/content/bindings/browser.xml :: loadURIWithFlags :: line 193" data: no]

__General Comments re this CHM Reader Application__
- possibly this software is now unsupported and abandoned
- - there is no active help site, afaik
- - the bugs appear not to be active, in that there is little or no response

__General Comments on Firefox Versions & Add-on compatibility.__
- from https://addons.mozilla.org/en-US/firefox/addon/chm-reader/ I note software detailed as "Updated July 8, 2008 ;Works with Firefox 3.0b4 - 3.6.* "
- it is in fact not unusual for firefox addon specified to work with fx v3.6 to work with fx v4 and above, even if it appears initially not compatible.
- ( iirc there were some changes in how fx 4 or 5 handles the sidebar - not sure if that affects this add-on).
- I have not yet tested this add-on on fx 4, fx5 or fx6

__ Other comments __
I am newbie on this site. Presumably there is a forum or other place more appropriate for discussion, if so I will also try to comments there and add links to and from this bug.
--- Compatibility Reporter
Readers of this bug, especially those with problems running it on fx 4 may be interested in this add-on https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/ Note despite the name the reporter not only provides feedback to developers it also allows fx4 to try otherwise incompatible add-ons
--- Modifying Compatibility
Readers may also be interested in a developers comments added as a review of his own add-on. It explains how to modify the compatibility of an add on, a similar method will allow CHM reader to be installed on fx 4 although the Compatibility reporter method (see above) is more user friendly.

--- Is this abandoned ?
If this has been abandoned I may consider either taking it over (if no one else is interested, or generating an add on with similar functions using sdk; unless there is anything similar already in existence [there is in other languages] I just like the idea of a method of reading chm, without needing Windows Explorer or Internet Explorer)

PS.
2nd attempt, at filing this bug, I hit return too early on first attempt