diff --git a/Assets/Cryville/Crtr/Browsing/LegacyResourceManager.cs b/Assets/Cryville/Crtr/Browsing/LegacyResourceManager.cs
index af18fe8..a3f4298 100644
--- a/Assets/Cryville/Crtr/Browsing/LegacyResourceManager.cs
+++ b/Assets/Cryville/Crtr/Browsing/LegacyResourceManager.cs
@@ -1,4 +1,4 @@
-using Cryville.Common;
+using Cryville.Common;
 using Cryville.Common.Unity;
 using Cryville.Crtr.Extension;
 using Cryville.Crtr.Extensions.Umg;
@@ -118,9 +118,12 @@ namespace Cryville.Crtr.Browsing {
 			IEnumerable<ResourceConverter> converters;
 			if (!ExtensionManager.TryGetConverters(file.Extension, out converters)) return false;
 			foreach (var converter in converters) {
-				IEnumerable<Resource> resources = null;
+				var resources = new List<Resource>();
+				var ses = new ConversionSession {
+					OnResourceAdd = res => resources.Add(res)
+				};
 				try {
-					resources = converter.ConvertFrom(file);
+					converter.Convert(file, ses);
 				}
 				catch (Exception ex) {
 					LogAndPopupExtra(4, ex, "Failed to import resource: {0}", ex.Message);
@@ -271,4 +274,4 @@ namespace Cryville.Crtr.Browsing {
 			}).ToList();
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/Assets/Cryville/Crtr/Extensions/Umg/ChartResourceImporter.cs b/Assets/Cryville/Crtr/Extensions/Umg/ChartResourceImporter.cs
index c30a840..28f8240 100644
--- a/Assets/Cryville/Crtr/Extensions/Umg/ChartResourceImporter.cs
+++ b/Assets/Cryville/Crtr/Extensions/Umg/ChartResourceImporter.cs
@@ -1,6 +1,5 @@
-using Cryville.Crtr.Extension;
+using Cryville.Crtr.Extension;
 using Newtonsoft.Json;
-using System.Collections.Generic;
 using System.IO;
 using System.Text;
 
@@ -11,12 +10,12 @@ namespace Cryville.Crtr.Extensions.Umg {
 			return SUPPORTED_FORMATS;
 		}
 
-		public override IEnumerable<Resource> ConvertFrom(FileInfo file) {
+		public override void Convert(FileInfo file, ConversionSession ses) {
 			var meta = Path.Combine(file.Directory.FullName, "meta.json");
 			if (!File.Exists(meta)) throw new FileNotFoundException("Meta file for the chart not found");
 			using (StreamReader reader = new StreamReader(meta, Encoding.UTF8)) {
 				var data = JsonConvert.DeserializeObject<ChartMeta>(reader.ReadToEnd());
-				return new Resource[] { new ChartResource(data.name, file) };
+				ses.AddResource(new ChartResource(data.name, file));
 			}
 		}
 	}
diff --git a/Assets/Cryville/Crtr/Extensions/Umg/RulesetResourceImporter.cs b/Assets/Cryville/Crtr/Extensions/Umg/RulesetResourceImporter.cs
index 24bf18c..d0e3e13 100644
--- a/Assets/Cryville/Crtr/Extensions/Umg/RulesetResourceImporter.cs
+++ b/Assets/Cryville/Crtr/Extensions/Umg/RulesetResourceImporter.cs
@@ -1,6 +1,5 @@
-using Cryville.Crtr.Extension;
+using Cryville.Crtr.Extension;
 using Newtonsoft.Json;
-using System.Collections.Generic;
 using System.IO;
 using System.Text;
 
@@ -11,10 +10,10 @@ namespace Cryville.Crtr.Extensions.Umg {
 			return SUPPORTED_FORMATS;
 		}
 
-		public override IEnumerable<Resource> ConvertFrom(FileInfo file) {
+		public override void Convert(FileInfo file, ConversionSession ses) {
 			using (StreamReader reader = new StreamReader(file.FullName, Encoding.UTF8)) {
 				var data = JsonConvert.DeserializeObject<Ruleset>(reader.ReadToEnd());
-				return new Resource[] { new RulesetResource(data.name, file) };
+				ses.AddResource(new RulesetResource(data.name, file));
 			}
 		}
 	}
diff --git a/Assets/Cryville/Crtr/Extensions/Umg/SkinResourceImporter.cs b/Assets/Cryville/Crtr/Extensions/Umg/SkinResourceImporter.cs
index 5420413..3500c77 100644
--- a/Assets/Cryville/Crtr/Extensions/Umg/SkinResourceImporter.cs
+++ b/Assets/Cryville/Crtr/Extensions/Umg/SkinResourceImporter.cs
@@ -1,6 +1,5 @@
-using Cryville.Crtr.Extension;
+using Cryville.Crtr.Extension;
 using Newtonsoft.Json;
-using System.Collections.Generic;
 using System.IO;
 using System.Text;
 
@@ -11,10 +10,10 @@ namespace Cryville.Crtr.Extensions.Umg {
 			return SUPPORTED_FORMATS;
 		}
 
-		public override IEnumerable<Resource> ConvertFrom(FileInfo file) {
+		public override void Convert(FileInfo file, ConversionSession ses) {
 			using (StreamReader reader = new StreamReader(file.FullName, Encoding.UTF8)) {
 				var data = JsonConvert.DeserializeObject<Skin>(reader.ReadToEnd());
-				return new Resource[] { new SkinResource(data.name, file) };
+				ses.AddResource(new SkinResource(data.name, file));
 			}
 		}
 	}
diff --git a/Assets/Plugins/Cryville.Crtr.Extension.dll b/Assets/Plugins/Cryville.Crtr.Extension.dll
index cfc4d44..95a617f 100644
Binary files a/Assets/Plugins/Cryville.Crtr.Extension.dll and b/Assets/Plugins/Cryville.Crtr.Extension.dll differ