Issue 5489 - ABP is disabled

mobile/android/app/mobile.js

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #filter substitution
 
 // For browser.xml binding
 //
 // cacheRatio* is a ratio that determines the amount of pixels to cache. The
 // ratio is multiplied by the viewport width or height to get the displayport's
@@ skipping 180 matching lines @@
 
 /* new html5 forms */
 pref("dom.experimental_forms", true);
 pref("dom.forms.number", true);
 
 /* extension manager and xpinstall */
 pref("xpinstall.whitelist.directRequest", false);
 pref("xpinstall.whitelist.fileRequest", false);
 pref("xpinstall.whitelist.add", "https://addons.mozilla.org,https://testpilot.firefox.com");
 
-pref("xpinstall.signatures.required", true);
+// Changed back to false. See https://issues.adblockplus.org/ticket/5489
+pref("xpinstall.signatures.required", false);
 
 pref("extensions.enabledScopes", 4);
 pref("extensions.autoupdate.enabled", true);
 pref("extensions.autoupdate.interval", 86400);
 pref("extensions.update.enabled", true);
 pref("extensions.update.interval", 86400);
 pref("extensions.dss.enabled", false);
 pref("extensions.dss.switchPending", false);
 pref("extensions.ignoreMTimeChanges", false);
 pref("extensions.logging.enabled", false);
@@ skipping 728 matching lines @@
 #endif
 
 pref("dom.audiochannel.audioCompeting", true);
 pref("dom.audiochannel.mediaControl", true);
 
 // Space separated list of URLS that are allowed to send objects (instead of
 // only strings) through webchannels. This list is duplicated in browser/app/profile/firefox.js
 pref("webchannel.allowObject.urlWhitelist", "https://accounts.firefox.com https://content.cdn.mozilla.net https://input.mozilla.org https://support.mozilla.org https://install.mozilla.org");
 
 pref("media.openUnsupportedTypeWithExternalApp", true);