1 files changed, 13 insertions, 13 deletions
diff --git a/application/palemoon/components/preferences/advanced.js b/application/palemoon/components/preferences/advanced.js
index 451af6f78..0803496fe 100644
--- a/application/palemoon/components/preferences/advanced.js
+++ b/application/palemoon/components/preferences/advanced.js
@@ -475,23 +475,23 @@ var gAdvancedPane = {
     var pm = Components.classes["@mozilla.org/permissionmanager;1"]
                        .getService(Components.interfaces.nsIPermissionManager);
     var perm = pm.getPermissionObject(principal, "offline-app");
-
-    // clear offline cache entries
-    var cacheService = Components.classes["@mozilla.org/network/application-cache-service;1"].
-                       getService(Components.interfaces.nsIApplicationCacheService);
-    var ios = Components.classes["@mozilla.org/network/io-service;1"].
-              getService(Components.interfaces.nsIIOService);
-    var groups = cacheService.getGroups();
-    for (var i = 0; i < groups.length; i++) {
-        var uri = ios.newURI(groups[i], null, null);
-        if (perm.matchesURI(uri, true)) {
+    if (perm) {
+      // clear offline cache entries
+      try {
+        var cacheService = Components.classes["@mozilla.org/network/application-cache-service;1"].
+                           getService(Components.interfaces.nsIApplicationCacheService);
+        var groups = cacheService.getGroups();
+        for (var i = 0; i < groups.length; i++) {
+          var uri = Services.io.newURI(groups[i], null, null);
+          if (perm.matchesURI(uri, true)) {
             var cache = cacheService.getActiveCache(groups[i]);
             cache.discard();
+          }
         }
-    }
-
-    pm.removePermission(perm);
+      } catch (e) {}
 
+      pm.removePermission(perm);
+    }
     list.removeChild(item);
     gAdvancedPane.offlineAppSelected();
     this.updateActualAppCacheSize();