diff --git a/src/Tree/Controllers/TreeController.cs b/src/Tree/Controllers/TreeController.cs
index 23dc8470652f880099fda4e1f6edfbb51a2544b3..3c4ee7a4a295f48a8d00aea14532b78872038e94 100644
--- a/src/Tree/Controllers/TreeController.cs
+++ b/src/Tree/Controllers/TreeController.cs
@@ -1,12 +1,15 @@
-using Coscine.WaterbutlerHelper;
-using Coscine.WaterbutlerHelper.ReturnObjects;
 using Coscine.ApiCommons;
 using Coscine.ApiCommons.Factories;
+using Coscine.Configuration;
 using Coscine.Database.DataModel;
 using Coscine.Database.Models;
 using Coscine.Database.Util;
 using Coscine.Logging;
 using Coscine.Metadata;
+using Coscine.ResourceLoader;
+using Coscine.ResourceTypeBase;
+using Coscine.WaterbutlerHelper;
+using Coscine.WaterbutlerHelper.ReturnObjects;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Logging;
@@ -20,9 +23,6 @@ using System.Web;
 using VDS.RDF;
 using VDS.RDF.Parsing;
 using VDS.RDF.Writing;
-using Coscine.ResourceLoader;
-using Coscine.Configuration;
-using Coscine.ResourceTypeBase;
 
 namespace Coscine.Api.Tree.Controllers
 {
@@ -81,7 +81,7 @@ namespace Coscine.Api.Tree.Controllers
         /// </summary>
         /// <param name="resourceId"> Id of a resource</param>
         /// <param name="path">Path to the file</param>
-        /// <returns> JSON Object with the metadata if ok, otherwise Statuscode 400 or 401 or 404</returns>
+        /// <returns> JSON Object with the metadata if OK, otherwise status code 400 or 401 or 404</returns>
         [HttpGet("[controller]/{resourceId}/{*path}")]
         public async Task<IActionResult> GetMetadata(string resourceId, string path = "")
         {
@@ -117,8 +117,8 @@ namespace Coscine.Api.Tree.Controllers
                 {
                     return BadRequest($"No provider for: \"{resource.Type.DisplayName}\".");
                 }
-                
-                var fileInfos = await resourceTypeDefinition.ListEntries(resourceId, path, resourceTypeOptions);
+
+                var fileInfos = await resourceTypeDefinition.ListEntries(null, path, resourceTypeOptions);
 
                 var metadataInfos = new List<ResourceEntry>(fileInfos);
                 if (path.EndsWith("/"))
@@ -126,7 +126,6 @@ namespace Coscine.Api.Tree.Controllers
                     metadataInfos.Insert(0, new ResourceEntry(path, false, 0, null, null, new DateTime(), new DateTime()));
                 }
 
-
                 var graphs = new List<JToken>();
                 int metadataCount = 0;
                 foreach (var info in metadataInfos)
@@ -211,7 +210,7 @@ namespace Coscine.Api.Tree.Controllers
         {
             var lastSlash = x.Key.LastIndexOf("/") + 1;
             var name = x.Key[lastSlash..];
-            if (name == "")
+            if (name?.Length == 0)
             {
                 var tempPath = x.Key[..(lastSlash - 1)];
                 if (tempPath.Contains("/"))
@@ -229,7 +228,7 @@ namespace Coscine.Api.Tree.Controllers
         /// </summary>
         /// <param name="resourceId">Id of the resource</param>
         /// <param name="path">Path to the file</param>
-        /// <returns>If ok Statuscode 204, otherwise Statuscode 400 or 401</returns>
+        /// <returns>If OK status code 204, otherwise status code 400 or 401</returns>
         [HttpPut("[controller]/{resourceId}/{*path}")]
         public IActionResult StoreMetadataForFile(string resourceId, string path)
         {
@@ -257,7 +256,7 @@ namespace Coscine.Api.Tree.Controllers
 
             if (resource.Archived == "1")
             {
-                return BadRequest("The resource is readonly!");
+                return BadRequest("The resource is read only!");
             }
 
             if (resource.ApplicationProfile[^1] != '/')
@@ -356,7 +355,6 @@ namespace Coscine.Api.Tree.Controllers
             _rdfStoreConnector.AddGraph(graph);
 
             return NoContent();
-
         }
 
         /// <summary>
@@ -365,7 +363,7 @@ namespace Coscine.Api.Tree.Controllers
         /// <param name="resourceId">Id of the resource</param>
         /// <param name="path">Path to the file</param>
         /// <param name="resource">Resource</param>
-        /// <returns>null, otherwise Statuscode  400 or 404 </returns>
+        /// <returns>null, otherwise status code  400 or 404 </returns>
         private IActionResult CheckResourceIdAndPath(string resourceId, string path, out Resource resource)
         {
             resource = null;
@@ -383,7 +381,7 @@ namespace Coscine.Api.Tree.Controllers
 
             if (!Guid.TryParse(resourceId, out Guid resourceGuid))
             {
-                return BadRequest($"{resourceId} is not a guid.");
+                return BadRequest($"{resourceId} is not a GUID.");
             }
 
             try
@@ -472,4 +470,4 @@ namespace Coscine.Api.Tree.Controllers
             return $"{present}/{total}";
         }
     }
-}
+}
\ No newline at end of file
diff --git a/src/Tree/Program.cs b/src/Tree/Program.cs
index 9f4c22ca9f7390cd4d5fda216a9ffeece503f083..0231458183aefb962a3d8f30debcdf54d16847d6 100644
--- a/src/Tree/Program.cs
+++ b/src/Tree/Program.cs
@@ -17,4 +17,4 @@ namespace Coscine.Api.Tree
             InitializeWebService<Startup>();
         }
     }
-}
+}
\ No newline at end of file
diff --git a/src/Tree/Startup.cs b/src/Tree/Startup.cs
index 38f4352c2b3044d7513c733bb6beede7fc0bb713..0f5f43fdb34d5884e923d0aa483cbc28b73466e5 100644
--- a/src/Tree/Startup.cs
+++ b/src/Tree/Startup.cs
@@ -1,5 +1,5 @@
-using Coscine.WaterbutlerHelper.Services;
-using Coscine.ApiCommons;
+using Coscine.ApiCommons;
+using Coscine.WaterbutlerHelper.Services;
 using Microsoft.Extensions.DependencyInjection;
 using System;
 
@@ -15,8 +15,8 @@ namespace Coscine.Api.Tree
         /// </summary>
         public Startup()
         {
-
         }
+
         /// <summary>
         /// Configures custom service extension
         /// </summary>
@@ -32,4 +32,4 @@ namespace Coscine.Api.Tree
             });
         }
     }
-}
+}
\ No newline at end of file
diff --git a/src/Tree/Tree.csproj b/src/Tree/Tree.csproj
index 2acee8e02a538c0449130b5ec0aa834f5be93f72..256a212193888dc7def92cd0b70abeddc7bb7a2f 100644
--- a/src/Tree/Tree.csproj
+++ b/src/Tree/Tree.csproj
@@ -22,6 +22,7 @@
 		<PackageReference Include="Coscine.Logging" Version="2.*-*" />
 		<PackageReference Include="Coscine.Metadata" Version="2.*-*" />
 		<PackageReference Include="Coscine.ResourceLoader" Version="2.*-*" />
+		<PackageReference Include="Coscine.ResourceTypeBase" Version="2.*-*" />
 		<PackageReference Include="Coscine.WaterbutlerHelper" Version="2.*-*" />
 	</ItemGroup>
-</Project>
\ No newline at end of file
+</Project>