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Updated to Firefox 76.0.1 and now I get the error "Failed to read the configuration file", config file is custom new tab

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  • 1 has this problem
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  • Last reply by cor-el

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I have recently updated to Firefox 76.0.1 and when I launch the browser I get the error "Failed to read the configuration file". When I delete the configuration file, this error no longer persists. I use the configuration for a custom new tab page. I found this issue and I have updated my file with the solution but this error still persists.

I have recently updated to Firefox 76.0.1 and when I launch the browser I get the error "Failed to read the configuration file". When I delete the configuration file, this error no longer persists. I use the configuration for a custom new tab page. I found this [https://support.mozilla.org/en-US/questions/1283835 issue] and I have updated my file with the solution but this error still persists.

Modified by Tyler Wolf

All Replies (5)

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Tyler Wolf said

I found this issue and I have updated my file with the solution but this error still persists.

So that is:

//
var {classes:Cc,interfaces:Ci,utils:Cu} = Components;
/* set new tab page */
try {
  Cu.import("resource:///modules/AboutNewTab.jsm");
  var newTabURL = "file:///C:/example.html";
  AboutNewTab.newTabURL = newTabURL;
} catch(e) {
  // report errors in the Browser Console
  Cu.reportError(e);
}

What is your current code? You can put <pre> before and </pre> after your code block so the forum doesn't mangle it. Also, you can change the URL after file:/// since we have no way of knowing what the correct file location is.

Modified by jscher2000 - Support Volunteer

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jscher2000 said

Tyler Wolf said

I found this issue and I have updated my file with the solution but this error still persists.

So that is:

//
var {classes:Cc,interfaces:Ci,utils:Cu} = Components;
/* set new tab page */
try {
  Cu.import("resource:///modules/AboutNewTab.jsm");
  var newTabURL = "file:///C:/example.html";
  AboutNewTab.newTabURL = newTabURL;
} catch(e) {
  // report errors in the Browser Console
  Cu.reportError(e);
}

What is your current code? You can put <pre> before and </pre> after your code block so the forum doesn't mangle it. Also, you can change the URL after file:/// since we have no way of knowing what the correct file location is.

The code of firefox.cfg is

//
var {classes:Cc,interfaces:Ci,utils:Cu} = Components;

/* set new tab page */
try {
  Cu.import("resource:///modules/AboutNewTab.jsm");
  var newTabURL = "file:///home/tyler/startpage/index.html";
  AboutNewTab.newTabURL = newTabURL;
} catch(e){Cu.reportError(e);} // report errors in the Browser Console

and the autoconfig.js is

// First line should be a comment
pref("general.config.filename", "firefox.cfg");
pref("general.config.obscure_value", 0);
pref("general.config.sandbox_enabled", false);

I have made sure that I have the correct path to the local file.

Modified by Tyler Wolf

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Did you check the Browser Console for more detail ?

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cor-el said

Did you check the Browser Console for more detail ?

I have attached the Browser Console here.

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This screenshot is with the two files in place and where you get the error alert ?

If you get the error message and nothing related in the Browser Console then it sounds that Firefox isn't finding the firefox.cfg file at all.

Where is Firefox installed (Home directory or root access location) ? Did you check the read/write permissions of both files ?

The autoconfig.js file that specifies to use autoconfig.cfg is placed into the "defaults/pref" directory where channel-prefs.js is located.

The autoconfig.cfg file is placed at the top level of the Firefox directory where you find the firefox startup script.

  • autoconfig.cfg and autoconfig.js need to start with a comment line (//)
  • autoconfig.js needs to use Unix line endings (LF instead of CR/LF)

See also: