diff --git a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/SharedFolders/FeatureSharedFolders.cs b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/SharedFolders/FeatureSharedFolders.cs
index e16abf6..a01c5f4 100644
--- a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/SharedFolders/FeatureSharedFolders.cs
+++ b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/SharedFolders/FeatureSharedFolders.cs
@@ -88,11 +88,12 @@ namespace Acacia.Features.SharedFolders
 
         private void AdditionalFolders_Sync(ZPushConnection connection)
         {
-            Logger.Instance.Debug(this, "Starting sync for account {0}", connection.Account);
-            using (SharedFoldersAPI api = new SharedFoldersAPI(connection))
+            using (SharedFoldersManager manager = Manage(connection.Account))
             {
+                Logger.Instance.Debug(this, "Starting sync for account {0}", connection.Account);
+
                 // Fetch the current shares
-                ICollection<SharedFolder> shares = api.GetCurrentShares();
+                ICollection<SharedFolder> shares = manager.GetCurrentShares(null);
                 Logger.Instance.Trace(this, "AdditionalFolders_Sync: {0}", shares.Count);
 
                 // Convert to dictionary
diff --git a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/SharedFolders/RemindersQuery.cs b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/SharedFolders/RemindersQuery.cs
index 9b15b0f..52504bb 100644
--- a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/SharedFolders/RemindersQuery.cs
+++ b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/SharedFolders/RemindersQuery.cs
@@ -98,6 +98,8 @@ namespace Acacia.Features.SharedFolders
         {
             Logger.Instance.Trace(this, "Setting reminders for folder {0}: {1}", wantReminders, folderId);
             string prefix = MakeFolderPrefix(folderId);
+            if (prefix == null)
+                return;
 
             // Find existing
             for (int i = 0; i < _queryCustom.Operands.Count;)
@@ -131,7 +133,11 @@ namespace Acacia.Features.SharedFolders
             // Collect the valid prefixes
             HashSet<string> prefixes = new HashSet<string>();
             foreach (SyncId id in wanted)
-                prefixes.Add(MakeFolderPrefix(id));
+            {
+                string prefix = MakeFolderPrefix(id);
+                if (prefix != null)
+                    prefixes.Add(prefix);
+            }
 
             // Remove all operands for which we do not want the prefix
             for (int i = 0; i < _queryCustom.Operands.Count;)
@@ -155,6 +161,10 @@ namespace Acacia.Features.SharedFolders
 
         private string MakeFolderPrefix(SyncId folderId)
         {
+            // Sanity check. The check for shared folders also excludes any weird ids; e.g. if permissions are wrong,
+            // this will not be a sync id, but a backend id.
+            if (folderId == null || !folderId.IsShared)
+                return null;
             return folderId.ToString() + ":";
         }
     }
diff --git a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/ZPush/API/SharedFolders/SharedFolder.cs b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/ZPush/API/SharedFolders/SharedFolder.cs
index 248424a..2d996d8 100644
--- a/src/AcaciaZPushPlugin/AcaciaZPushPlugin/ZPush/API/SharedFolders/SharedFolder.cs
+++ b/src/AcaciaZPushPlugin/AcaciaZPushPlugin/ZPush/API/SharedFolders/SharedFolder.cs
@@ -20,7 +20,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
-using static Acacia.ZPush.API.SharedFolders.SharedFoldersAPI;
 
 namespace Acacia.ZPush.API.SharedFolders
 {