diff -up comm-esr31/mail/app/profile/all-thunderbird.js.addons comm-esr31/mail/app/profile/all-thunderbird.js

--- comm-esr31/mail/app/profile/all-thunderbird.js.addons	2014-07-18 02:04:05.000000000 +0200

+++ comm-esr31/mail/app/profile/all-thunderbird.js	2014-07-29 15:29:11.949728141 +0200

@@ -174,7 +174,7 @@ pref("extensions.update.autoUpdateDefaul

 // Disable add-ons installed into the shared user and shared system areas by

 // default. This does not include the application directory. See the SCOPE

 // constants in AddonManager.jsm for values to use here

-pref("extensions.autoDisableScopes", 15);

+pref("extensions.autoDisableScopes", 0);

 // Preferences for AMO integration

 pref("extensions.getAddons.cache.enabled", true);

diff -up comm-esr31/mozilla/toolkit/mozapps/extensions/internal/XPIProvider.jsm.addons comm-esr31/mozilla/toolkit/mozapps/extensions/internal/XPIProvider.jsm

--- comm-esr31/mozilla/toolkit/mozapps/extensions/internal/XPIProvider.jsm.addons	2014-07-29 15:29:11.951728146 +0200

+++ comm-esr31/mozilla/toolkit/mozapps/extensions/internal/XPIProvider.jsm	2014-07-29 15:30:51.879030210 +0200

@@ -1894,8 +1894,8 @@ this.XPIProvider = {

         this.showUpgradeUI();

         flushCaches = true;

       }

-      else if (aAppChanged === undefined) {

-        // For new profiles we will never need to show the add-on selection UI

+      else {

+        // For all profiles we will never need to show the add-on selection UI

         Services.prefs.setBoolPref(PREF_SHOWN_SELECTION_UI, true);

       }