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Studio User Guide

Last updated Jul 29, 2025

Extension on Firefox versions older than v128 or v115 ESR

According to Mozilla announcement about Firefox's root certificate expiration on March 14, 2025, extensions fail to install in Firefox versions older than v128 or v115.13 ESR.
  • If the extension is already installed in Firefox, it will continue to work even after the root certificate expires.
  • If the extension is installed after the root certificate expires, it will be disabled and will not work.

You can apply certain workarounds, but this depends on how old your Firefox version is and whether or not it is an ESR (Extended Support Release) version.

Solution for Firefox ESR

  1. Go to about:config.
  2. Toggle xpinstall.signatures.required flag to false.

It is preferable to automatically apply this setting to all profiles using one of the methods listed below.

Firefox v102.10 ESR or newer

You can use Group Policy to modify the xpinstall.signatures.required preference for all users and profiles automatically. For more details, refer to Policy Templates for Firefox.

Firefox older than v102.10 ESR

Older versions of Firefox do not support xpinstall.signatures.required through Group Policy. As an alternative, you can use AutoConfig files:
  1. Save the following inside a text file:
    // First line must be a comment.
    pref("xpinstall.signatures.required", false);// First line must be a comment.
    pref("xpinstall.signatures.required", false);
  2. Name the text file allow-unsigned-extensions.cfg.
  3. Save the following inside a text file:
    // First line must be a comment. 
    pref("general.config.filename", "allow-unsigned-extensions.cfg"); pref("general.config.obscure_value", 0);// First line must be a comment. 
    pref("general.config.filename", "allow-unsigned-extensions.cfg"); pref("general.config.obscure_value", 0);
  4. Name the text file allow-unsigned-extensions.js.
  5. Find the Firefox install directory, typically C:\Program Files\Mozilla Firefox.
  6. Copy allow-unsigned-extensions.cfg to C:\Program Files\Mozilla Firefox.
  7. Copy allow-unsigned-extensions.js to C:\Program Files\Mozilla Firefox\pref.

Firefox - normal releases

For non-ESR releases of Firefox, you must use AutoConfig files.

  1. Save the following inside a text file:
    // First line must be a comment.
    
    // In Firefox 55+, settings to configure add-on signing (and legacy add-ons) are stored in AddonSettings.jsm
    // The module exports an object with read-only properties, but that is not an issue since we can just replace
    // the exported object.
    // https://searchfox.org/mozilla-central/rev/2e08acdf8862e68b13166970e17809a3b5d6a555/toolkit/mozapps/extensions/internal/AddonSettings.jsm
    
    Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
    
    function patchAddonSettings(modulePath) {
        var Module = Components.utils.import(modulePath, {});
        // Note: we read the data from preferences instead of hard-coding a "true", so
        // that by default legacy add-ons are disabled. This enables the user to only
        // enable legacy add-ons for specific Firefox profiles when really needed.
        var AddonSettings;
    
        if ("lazy" in Module) {
          AddonSettings = Object.create(Module.lazy.AddonSettings);
        } else {
          AddonSettings = Object.create(Module.AddonSettings);
        }
        XPCOMUtils.defineLazyPreferenceGetter(AddonSettings, "REQUIRE_SIGNING", "xpinstall.signatures.required", false);
        XPCOMUtils.defineLazyPreferenceGetter(AddonSettings, "ALLOW_LEGACY_EXTENSIONS", "extensions.legacy.enabled", true);
        XPCOMUtils.defineLazyPreferenceGetter(AddonSettings, "LANGPACKS_REQUIRE_SIGNING", "extensions.langpacks.signatures.required", false);
    
        if ("lazy" in Module) {
          Module.lazy.AddonSettings = AddonSettings;
        } else {
          Module.AddonSettings = AddonSettings;
        }
    }
    
    // This is necessary to allow legacy add-ons via preferences.
    try {
      patchAddonSettings("resource://gre/modules/addons/XPIProvider.jsm");
    } catch (e) {
      // AddonSettings is not in this file starting with Firefox 61,
      // but it comes back in Firefox 74
    }
    
    try {
      patchAddonSettings("resource://gre/modules/addons/XPIDatabase.jsm");
    } catch (e) {
      // AddonSettings is not in this file until Firefox 61
    }
    
    // This override is needed to enable unsigned add-ons via preferences.
    patchAddonSettings("resource://gre/modules/addons/XPIInstall.jsm");
    
    // This override is needed to allow unsigned add-ons to show up without warning in about:addons.
    // (this is UI-only, the add-on is not actually disabled despite what the UI claims).
    patchAddonSettings("resource://gre/modules/addons/AddonSettings.jsm");
    
    Components.classes['@mozilla.org/consoleservice;1']
    .getService(Components.interfaces.nsIConsoleService)
    .logStringMessage("enablelegacy.cfg: the extensions.legacy.enabled preference is working again.");
    
    pref("xpinstall.signatures.required", false);// First line must be a comment.
    
    // In Firefox 55+, settings to configure add-on signing (and legacy add-ons) are stored in AddonSettings.jsm
    // The module exports an object with read-only properties, but that is not an issue since we can just replace
    // the exported object.
    // https://searchfox.org/mozilla-central/rev/2e08acdf8862e68b13166970e17809a3b5d6a555/toolkit/mozapps/extensions/internal/AddonSettings.jsm
    
    Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
    
    function patchAddonSettings(modulePath) {
        var Module = Components.utils.import(modulePath, {});
        // Note: we read the data from preferences instead of hard-coding a "true", so
        // that by default legacy add-ons are disabled. This enables the user to only
        // enable legacy add-ons for specific Firefox profiles when really needed.
        var AddonSettings;
    
        if ("lazy" in Module) {
          AddonSettings = Object.create(Module.lazy.AddonSettings);
        } else {
          AddonSettings = Object.create(Module.AddonSettings);
        }
        XPCOMUtils.defineLazyPreferenceGetter(AddonSettings, "REQUIRE_SIGNING", "xpinstall.signatures.required", false);
        XPCOMUtils.defineLazyPreferenceGetter(AddonSettings, "ALLOW_LEGACY_EXTENSIONS", "extensions.legacy.enabled", true);
        XPCOMUtils.defineLazyPreferenceGetter(AddonSettings, "LANGPACKS_REQUIRE_SIGNING", "extensions.langpacks.signatures.required", false);
    
        if ("lazy" in Module) {
          Module.lazy.AddonSettings = AddonSettings;
        } else {
          Module.AddonSettings = AddonSettings;
        }
    }
    
    // This is necessary to allow legacy add-ons via preferences.
    try {
      patchAddonSettings("resource://gre/modules/addons/XPIProvider.jsm");
    } catch (e) {
      // AddonSettings is not in this file starting with Firefox 61,
      // but it comes back in Firefox 74
    }
    
    try {
      patchAddonSettings("resource://gre/modules/addons/XPIDatabase.jsm");
    } catch (e) {
      // AddonSettings is not in this file until Firefox 61
    }
    
    // This override is needed to enable unsigned add-ons via preferences.
    patchAddonSettings("resource://gre/modules/addons/XPIInstall.jsm");
    
    // This override is needed to allow unsigned add-ons to show up without warning in about:addons.
    // (this is UI-only, the add-on is not actually disabled despite what the UI claims).
    patchAddonSettings("resource://gre/modules/addons/AddonSettings.jsm");
    
    Components.classes['@mozilla.org/consoleservice;1']
    .getService(Components.interfaces.nsIConsoleService)
    .logStringMessage("enablelegacy.cfg: the extensions.legacy.enabled preference is working again.");
    
    pref("xpinstall.signatures.required", false);
    
  2. Name the text file enable-legacy.cfg.
  3. Save the following inside a text file:
    // First line must be a comment. pref("general.config.filename", "enablelegacy.cfg"); 
    pref("general.config.obscure_value", 0); pref("general.config.sandbox_enabled", false);// First line must be a comment. pref("general.config.filename", "enablelegacy.cfg"); 
    pref("general.config.obscure_value", 0); pref("general.config.sandbox_enabled", false);
  4. Name the text file enablelegacy-prefs.js.
  5. Find the Firefox install directory, typically C:\Program Files\Mozilla Firefox.
  6. Copy allow-unsigned-extensions.cfg to C:\Program Files\Mozilla Firefox.
  7. Copy allow-unsigned-extensions.js to C:\Program Files\Mozilla Firefox\defaults\pref.
Note:

Recent versions of Firefox, like 102.10 ESR, re-enable the extension automatically once the flag is set. In older versions such as 68.0.2 ESR, it may be necessary to reinstall the extension.

The Group Policy Offline installation method does not work with Firefox 68.0.2 ESR and possibly older versions. A temporary workaround involves adding the following to a PowerShell script and running it with administrator privileges:

# Define the registry path
$regPath = "HKLM:\SOFTWARE\Policies\Mozilla\Firefox\Extensions\Install"

function Convert-WindowsPathToFileUrl($path) {
    $unixPath = $path -replace '\\', '/'
    $escapedPath = $unixPath -replace ' ', '%20'
    return "file:///" + $escapedPath
}

function Fix-FirefoxProfile($prefsPath, $fileUrl) {
    if (-not (Test-Path $prefsPath)) {
        Write-Host "prefs.js not found: $prefsPath"
        return
    }

    Write-Host "Processing prefs.js: $prefsPath"

    $content = Get-Content -Path $prefsPath -Raw

    $pattern = 'user_pref\("browser\.policies\.runOncePerModification\.extensionsInstall",\s*"(.+?)"\);'

    if (-not ($content -match $pattern)) {
        Write-Host " -> No matching preference found in prefs.js."
        return
    }

    $jsonArrayString = $matches[1]

    # Unescape \" to "
    $jsonArrayStringUnescaped = $jsonArrayString -replace '\\\"', '"'

    try {
        $list = ConvertFrom-Json -InputObject $jsonArrayStringUnescaped
    } catch {
        Write-Host " -> Error parsing JSON inside prefs.js preference (after unescaping)."
        return
    }

    if (-not ($list -contains $fileUrl)) {
        Write-Host " -> File URL not present in extensionsInstall list."
        return
    }

    $newList = $list | Where-Object { $_ -ne $fileUrl }

    $newJsonArrayString = ($newList | ConvertTo-Json -Compress)

    # prefs.js expects it wrapped as a string, escaping " as \"
    $escapedNewJsonArrayString = $newJsonArrayString -replace '"', '\"'

    $newPrefLine = "user_pref(""browser.policies.runOncePerModification.extensionsInstall"", `"$escapedNewJsonArrayString`");"

    # Replace the old line
    $oldPrefLine = $matches[0]
    $content = $content -replace [regex]::Escape($oldPrefLine), $newPrefLine

    Set-Content -Path $prefsPath -Value $content -Encoding UTF8
    Write-Host " -> prefs.js updated."
}

function Fix-AllFirefoxProfiles($fileUrl) {
    $profilesPath = "$env:APPDATA\Mozilla\Firefox\Profiles"

    if (-not (Test-Path $profilesPath)) {
        Write-Host "Firefox profiles directory not found: $profilesPath"
        return
    }

    $profiles = Get-ChildItem -Path $profilesPath -Directory
    foreach ($profile in $profiles) {
        $prefsPath = Join-Path $profile.FullName "prefs.js"
        Fix-FirefoxProfile -prefsPath $prefsPath -fileUrl $fileUrl
    }
}

if (-not (Test-Path $regPath)) {
    Write-Host "Registry path not found: $regPath"
    return
}

$values = Get-ItemProperty -Path $regPath

foreach ($property in $values.PSObject.Properties) {
    $name = $property.Name
    $value = $property.Value

    if ($value -notmatch "^[a-zA-Z]:\\.*\\uipath-ff\.xpi$") {
        continue
    }

    Write-Host "Found Windows path for uipath-ff.xpi in entry '$name': $value"

    $fileUrl = Convert-WindowsPathToFileUrl $value
    Write-Host " -> Converted to file URL: $fileUrl"

    Set-ItemProperty -Path $regPath -Name $name -Value $fileUrl
    Write-Host " -> Updated registry key '$name'."

    Fix-AllFirefoxProfiles -fileUrl $fileUrl
}# Define the registry path
$regPath = "HKLM:\SOFTWARE\Policies\Mozilla\Firefox\Extensions\Install"

function Convert-WindowsPathToFileUrl($path) {
    $unixPath = $path -replace '\\', '/'
    $escapedPath = $unixPath -replace ' ', '%20'
    return "file:///" + $escapedPath
}

function Fix-FirefoxProfile($prefsPath, $fileUrl) {
    if (-not (Test-Path $prefsPath)) {
        Write-Host "prefs.js not found: $prefsPath"
        return
    }

    Write-Host "Processing prefs.js: $prefsPath"

    $content = Get-Content -Path $prefsPath -Raw

    $pattern = 'user_pref\("browser\.policies\.runOncePerModification\.extensionsInstall",\s*"(.+?)"\);'

    if (-not ($content -match $pattern)) {
        Write-Host " -> No matching preference found in prefs.js."
        return
    }

    $jsonArrayString = $matches[1]

    # Unescape \" to "
    $jsonArrayStringUnescaped = $jsonArrayString -replace '\\\"', '"'

    try {
        $list = ConvertFrom-Json -InputObject $jsonArrayStringUnescaped
    } catch {
        Write-Host " -> Error parsing JSON inside prefs.js preference (after unescaping)."
        return
    }

    if (-not ($list -contains $fileUrl)) {
        Write-Host " -> File URL not present in extensionsInstall list."
        return
    }

    $newList = $list | Where-Object { $_ -ne $fileUrl }

    $newJsonArrayString = ($newList | ConvertTo-Json -Compress)

    # prefs.js expects it wrapped as a string, escaping " as \"
    $escapedNewJsonArrayString = $newJsonArrayString -replace '"', '\"'

    $newPrefLine = "user_pref(""browser.policies.runOncePerModification.extensionsInstall"", `"$escapedNewJsonArrayString`");"

    # Replace the old line
    $oldPrefLine = $matches[0]
    $content = $content -replace [regex]::Escape($oldPrefLine), $newPrefLine

    Set-Content -Path $prefsPath -Value $content -Encoding UTF8
    Write-Host " -> prefs.js updated."
}

function Fix-AllFirefoxProfiles($fileUrl) {
    $profilesPath = "$env:APPDATA\Mozilla\Firefox\Profiles"

    if (-not (Test-Path $profilesPath)) {
        Write-Host "Firefox profiles directory not found: $profilesPath"
        return
    }

    $profiles = Get-ChildItem -Path $profilesPath -Directory
    foreach ($profile in $profiles) {
        $prefsPath = Join-Path $profile.FullName "prefs.js"
        Fix-FirefoxProfile -prefsPath $prefsPath -fileUrl $fileUrl
    }
}

if (-not (Test-Path $regPath)) {
    Write-Host "Registry path not found: $regPath"
    return
}

$values = Get-ItemProperty -Path $regPath

foreach ($property in $values.PSObject.Properties) {
    $name = $property.Name
    $value = $property.Value

    if ($value -notmatch "^[a-zA-Z]:\\.*\\uipath-ff\.xpi$") {
        continue
    }

    Write-Host "Found Windows path for uipath-ff.xpi in entry '$name': $value"

    $fileUrl = Convert-WindowsPathToFileUrl $value
    Write-Host " -> Converted to file URL: $fileUrl"

    Set-ItemProperty -Path $regPath -Name $name -Value $fileUrl
    Write-Host " -> Updated registry key '$name'."

    Fix-AllFirefoxProfiles -fileUrl $fileUrl
}

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