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 +174,8 @@ 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);
+pref("extensions.showMismatchUI", false);
 
 // Preferences for AMO integration
 pref("extensions.getAddons.cache.enabled", true);