diff --git a/src/js/assets.js b/src/js/assets.js
index 056410416..79a05c380 100644
--- a/src/js/assets.js
+++ b/src/js/assets.js
@@ -67,7 +67,7 @@ var exports = {
     autoUpdateDelay: 4 * oneDay,
 
     // https://github.com/gorhill/uBlock/issues/426
-    allowRemoteFetch: true
+    remoteFetchBarrier: 0
 };
 
 /******************************************************************************/
@@ -358,7 +358,7 @@ var getRepoMetadata = function(callback) {
         return;
     }
 
-    if ( exports.allowRemoteFetch && lastRepoMetaIsRemote === false ) {
+    if ( exports.remoteFetchBarrier === 0 && lastRepoMetaIsRemote === false ) {
         lastRepoMetaTimestamp = 0;
     }
     if ( (Date.now() - lastRepoMetaTimestamp) >= refreshRepoMetaPeriod ) {
@@ -370,7 +370,7 @@ var getRepoMetadata = function(callback) {
     }
 
     lastRepoMetaTimestamp = Date.now();
-    lastRepoMetaIsRemote = exports.allowRemoteFetch;
+    lastRepoMetaIsRemote = exports.remoteFetchBarrier === 0;
 
     var localChecksums;
     var repoChecksums;
@@ -528,7 +528,7 @@ var readLocalFile = function(path, callback) {
 
 var readRepoFile = function(path, callback) {
     // https://github.com/gorhill/uBlock/issues/426
-    if ( exports.allowRemoteFetch === false ) {
+    if ( exports.remoteFetchBarrier !== 0 ) {
         readLocalFile(path, callback);
         return;
     }
@@ -668,7 +668,10 @@ var readRepoCopyAsset = function(path, callback) {
         // - Auto-update enabled AND (not in cache OR in cache but obsolete)
         var timestamp = entries[path];
         var inCache = typeof timestamp === 'number';
-        if ( exports.allowRemoteFetch && exports.autoUpdate && stringIsNotEmpty(homeURL) ) {
+        if (
+            exports.remoteFetchBarrier === 0 &&
+            exports.autoUpdate && stringIsNotEmpty(homeURL)
+        ) {
             if ( inCache === false || cacheIsObsolete(timestamp) ) {
                 //console.log('µBlock> readRepoCopyAsset("%s") / onCacheMetaReady(): not cached or obsolete', path);
                 getTextFileFromURL(homeURL, onHomeFileLoaded, onHomeFileError);
@@ -696,7 +699,11 @@ var readRepoCopyAsset = function(path, callback) {
         }
 
         // Repo copy changed: fetch from home URL
-        if ( exports.allowRemoteFetch && exports.autoUpdate && assetEntry.localChecksum !== assetEntry.repoChecksum ) {
+        if (
+            exports.remoteFetchBarrier === 0 &&
+            exports.autoUpdate &&
+            assetEntry.localChecksum !== assetEntry.repoChecksum
+        ) {
             //console.log('µBlock> readRepoCopyAsset("%s") / onRepoMetaReady(): repo has newer version', path);
             if ( stringIsNotEmpty(homeURL) ) {
                 getTextFileFromURL(homeURL, onHomeFileLoaded, onHomeFileError);
@@ -793,7 +800,11 @@ var readRepoOnlyAsset = function(path, callback) {
         }
 
         // Asset added or changed: load from repo URL and then cache result
-        if ( exports.allowRemoteFetch && exports.autoUpdate && assetEntry.localChecksum !== assetEntry.repoChecksum ) {
+        if (
+            exports.remoteFetchBarrier === 0 &&
+            exports.autoUpdate &&
+            assetEntry.localChecksum !== assetEntry.repoChecksum
+        ) {
             //console.log('µBlock> readRepoOnlyAsset("%s") / onRepoMetaReady(): repo has newer version', path);
             getTextFileFromURL(repositoryURL, onRepoFileLoaded, onRepoFileError);
             return;
@@ -872,7 +883,9 @@ var readExternalAsset = function(path, callback) {
         // - Auto-update enabled AND in cache but obsolete
         var timestamp = entries[path];
         var notInCache = typeof timestamp !== 'number';
-        var updateCache = exports.allowRemoteFetch && exports.autoUpdate && cacheIsObsolete(timestamp);
+        var updateCache = exports.remoteFetchBarrier === 0 &&
+                          exports.autoUpdate &&
+                          cacheIsObsolete(timestamp);
         if ( notInCache || updateCache ) {
             getTextFileFromURL(path, onExternalFileLoaded, onExternalFileError);
             return;
@@ -1150,6 +1163,7 @@ var onOneUpdated = function(details) {
 
     var path = details.path;
     if ( details.error ) {
+        manualUpdateNotify(false, updatedCount / (updatedCount + toUpdateCount));
         //console.debug('µBlock.assetUpdater/onOneUpdated: "%s" failed', path);
         return;
     }
diff --git a/src/js/start.js b/src/js/start.js
index 16a370ee3..2892d4987 100644
--- a/src/js/start.js
+++ b/src/js/start.js
@@ -51,13 +51,16 @@ var onAllReady = function() {
 
     // Important: remove barrier to remote fetching, this was useful only
     // for launch time.
-    µb.assets.allowRemoteFetch = true;
+    µb.assets.remoteFetchBarrier -= 1;
 
     //quickProfiler.stop(0);
 
     vAPI.onLoadAllCompleted();
 };
 
+// Forbid remote fetching of assets
+µb.assets.remoteFetchBarrier += 1;
+
 /******************************************************************************/
 
 // Filtering engines dependencies:
@@ -126,7 +129,6 @@ var onUserSettingsReady = function(fetched) {
     // https://github.com/gorhill/uBlock/issues/426
     // Important: block remote fetching for when loading assets at launch
     // time.
-    µb.assets.allowRemoteFetch = false;
     µb.assets.autoUpdate = userSettings.autoUpdate;
     µb.assets.autoUpdateDelay = µb.updateAssetsEvery;
 
diff --git a/src/js/storage.js b/src/js/storage.js
index 04e6c0cbf..0e216971b 100644
--- a/src/js/storage.js
+++ b/src/js/storage.js
@@ -282,7 +282,14 @@
         callback = this.noopFunc;
     }
 
+    // Never fetch from remote servers when we load filter lists: this has to
+    // be as fast as possible.
+    µb.assets.remoteFetchBarrier += 1;
+
     var onDone = function() {
+        // Remove barrier to remote fetching
+        µb.assets.remoteFetchBarrier -= 1;
+
         µb.staticNetFilteringEngine.freeze();
         µb.cosmeticFilteringEngine.freeze();
         vAPI.storage.set({ 'remoteBlacklists': µb.remoteBlacklists });
@@ -683,12 +690,12 @@
     var µb = this;
     var updatedCount = details.updatedCount;
 
-    // Assets are supposed to have been all updated, avoid fetching from
+    // Assets are supposed to have been all updated, prevent fetching from
     // remote servers.
-    µb.assets.allowRemoteFetch = false;
+    µb.assets.remoteFetchBarrier += 1;
 
     var onFiltersReady = function() {
-        µb.assets.allowRemoteFetch = true;
+        µb.assets.remoteFetchBarrier -= 1;
     };
 
     var onPSLReady = function() {