I'm running into this error: Error loading "desert". Cannot find type TiledLib.MapContent, TiledLib, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null. at Microsoft.Xna.Framework.Content.ContentTypeReaderManager.InstantiateTypeReader(String readerTypeName, ContentReader contentReader, ContentTypeReader& reader) at Microsoft.Xna.Framework.Content.ContentTypeReaderManager.GetTypeReader(String readerTypeName, ContentReader contentReader, List1& newTypeReaders) at Microsoft.Xna.Framework.Content.ContentTypeReaderManager.ReadTypeManifest(Int32 typeCount, ContentReader contentReader) at Microsoft.Xna.Framework.Content.ContentReader.ReadHeader() at Microsoft.Xna.Framework.Content.ContentReader.ReadAsset[T]() at Microsoft.Xna.Framework.Content.ContentManager.ReadAsset[T](String assetName, Action1 recordDisposableObject) at Microsoft.Xna.Framework.Content.ContentManager.Load[T](String assetName) at TiledTest.Game1.LoadContent() in C:\My Documents\Dropbox\Visual Studio Projects\TiledTest\TiledTest\TiledTest\Game1.cs:line 51 at Microsoft.Xna.Framework.Game.Initialize() at TiledTest.Game1.Initialize() in C:\My Documents\Dropbox\Visual Studio Projects\TiledTest\TiledTest\TiledTest\Game1.cs:line 39 at Microsoft.Xna.Framework.Game.RunGame(Boolean useBlockingRun) at Microsoft.Xna.Framework.Game.Run() at TiledTest.Program.Main(String[] args) in C:\My Documents\Dropbox\Visual Studio Projects\TiledTest\TiledTest\TiledTest\Program.cs:line 15 When trying to run the game. This is a basic demo to try and utilize a separate project library called TiledLib. I have four projects overall: TiledLib (C# Class Library) TiledTest (Windows Game) TiledTestContent (Content) TMX CP Ext (Content Pipeline Extension Library) TiledLib contains MapContent which is throwing the error, however I believe this may just be a generic error with a deeper root problem. EMX CP Ext contains one file: MapProcessor.cs using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Content.Pipeline; using Microsoft.Xna.Framework.Content.Pipeline.Graphics; using Microsoft.Xna.Framework.Content.Pipeline.Processors; using Microsoft.Xna.Framework.Content; using TiledLib; namespace TMX_CP_Ext { // Each tile has a texture, source rect, and sprite effects. [ContentSerializerRuntimeType("TiledTest.Tile, TiledTest")] public class DemoMapTileContent { public ExternalReference<Texture2DContent> Texture; public Rectangle SourceRectangle; public SpriteEffects SpriteEffects; } // For each layer, we store the size of the layer and the tiles. [ContentSerializerRuntimeType("TiledTest.Layer, TiledTest")] public class DemoMapLayerContent { public int Width; public int Height; public DemoMapTileContent[] Tiles; } // For the map itself, we just store the size, tile size, and a list of layers. [ContentSerializerRuntimeType("TiledTest.Map, TiledTest")] public class DemoMapContent { public int TileWidth; public int TileHeight; public List<DemoMapLayerContent> Layers = new List<DemoMapLayerContent>(); } [ContentProcessor(DisplayName = "TMX Processor - TiledLib")] public class MapProcessor : ContentProcessor<MapContent, DemoMapContent> { public override DemoMapContent Process(MapContent input, ContentProcessorContext context) { // build the textures TiledHelpers.BuildTileSetTextures(input, context); // generate source rectangles TiledHelpers.GenerateTileSourceRectangles(input); // now build our output, first by just copying over some data DemoMapContent output = new DemoMapContent { TileWidth = input.TileWidth, TileHeight = input.TileHeight }; // iterate all the layers of the input foreach (LayerContent layer in input.Layers) { // we only care about tile layers in our demo TileLayerContent tlc = layer as TileLayerContent; if (tlc != null) { // create the new layer DemoMapLayerContent outLayer = new DemoMapLayerContent { Width = tlc.Width, Height = tlc.Height, }; // we need to build up our tile list now outLayer.Tiles = new DemoMapTileContent[tlc.Data.Length]; for (int i = 0; i < tlc.Data.Length; i++) { // get the ID of the tile uint tileID = tlc.Data[i]; // use that to get the actual index as well as the SpriteEffects int tileIndex; SpriteEffects spriteEffects; TiledHelpers.DecodeTileID(tileID, out tileIndex, out spriteEffects); // figure out which tile set has this tile index in it and grab // the texture reference and source rectangle. ExternalReference<Texture2DContent> textureContent = null; Rectangle sourceRect = new Rectangle(); // iterate all the tile sets foreach (var tileSet in input.TileSets) { // if our tile index is in this set if (tileIndex - tileSet.FirstId < tileSet.Tiles.Count) { // store the texture content and source rectangle textureContent = tileSet.Texture; sourceRect = tileSet.Tiles[(int)(tileIndex - tileSet.FirstId)].Source; // and break out of the foreach loop break; } } // now insert the tile into our output outLayer.Tiles[i] = new DemoMapTileContent { Texture = textureContent, SourceRectangle = sourceRect, SpriteEffects = spriteEffects }; } // add the layer to our output output.Layers.Add(outLayer); } } // return the output object. because we have ContentSerializerRuntimeType attributes on our // objects, we don't need a ContentTypeWriter and can just use the automatic serialization. return output; } } } TiledLib contains a large amount of files including MapContent.cs using System; using System.Collections.Generic; using System.Globalization; using System.Xml; using Microsoft.Xna.Framework.Content.Pipeline; namespace TiledLib { public enum Orientation : byte { Orthogonal, Isometric, } public class MapContent { public string Filename; public string Directory; public string Version = string.Empty; public Orientation Orientation; public int Width; public int Height; public int TileWidth; public int TileHeight; public PropertyCollection Properties = new PropertyCollection(); public List<TileSetContent> TileSets = new List<TileSetContent>(); public List<LayerContent> Layers = new List<LayerContent>(); public MapContent(XmlDocument document, ContentImporterContext context) { XmlNode mapNode = document["map"]; Version = mapNode.Attributes["version"].Value; Orientation = (Orientation)Enum.Parse(typeof(Orientation), mapNode.Attributes["orientation"].Value, true); Width = int.Parse(mapNode.Attributes["width"].Value, CultureInfo.InvariantCulture); Height = int.Parse(mapNode.Attributes["height"].Value, CultureInfo.InvariantCulture); TileWidth = int.Parse(mapNode.Attributes["tilewidth"].Value, CultureInfo.InvariantCulture); TileHeight = int.Parse(mapNode.Attributes["tileheight"].Value, CultureInfo.InvariantCulture); XmlNode propertiesNode = document.SelectSingleNode("map/properties"); if (propertiesNode != null) { Properties = new PropertyCollection(propertiesNode, context); } foreach (XmlNode tileSet in document.SelectNodes("map/tileset")) { if (tileSet.Attributes["source"] != null) { TileSets.Add(new ExternalTileSetContent(tileSet, context)); } else { TileSets.Add(new TileSetContent(tileSet, context)); } } foreach (XmlNode layerNode in document.SelectNodes("map/layer|map/objectgroup")) { LayerContent layerContent; if (layerNode.Name == "layer") { layerContent = new TileLayerContent(layerNode, context); } else if (layerNode.Name == "objectgroup") { layerContent = new MapObjectLayerContent(layerNode, context); } else { throw new Exception("Unknown layer name: " + layerNode.Name); } // Layer names need to be unique for our lookup system, but Tiled // doesn't require unique names. string layerName = layerContent.Name; int duplicateCount = 2; // if a layer already has the same name... if (Layers.Find(l => l.Name == layerName) != null) { // figure out a layer name that does work do { layerName = string.Format("{0}{1}", layerContent.Name, duplicateCount); duplicateCount++; } while (Layers.Find(l => l.Name == layerName) != null); // log a warning for the user to see context.Logger.LogWarning(string.Empty, new ContentIdentity(), "Renaming layer \"{1}\" to \"{2}\" to make a unique name.", layerContent.Type, layerContent.Name, layerName); // save that name layerContent.Name = layerName; } Layers.Add(layerContent); } } } } I'm lost as to why this is failing. Thoughts? -- EDIT -- After playing with it a bit, I would think it has something to do with referencing the projects. I'm already referencing the TiledLib within my main windows project (TiledTest). However, this doesn't seem to make a difference. I can place the dll generated from the TiledLib project into the debug folder of TiledTest, and this causes it to generate a different error: Error loading "desert". Cannot find ContentTypeReader for Microsoft.Xna.Framework.Content.Pipeline.ExternalReference`1[Microsoft.Xna.Framework.Content.Pipeline.Graphics.Texture2DContent]. at Microsoft.Xna.Framework.Content.ContentTypeReaderManager.GetTypeReader(Type targetType, ContentReader contentReader) at Microsoft.Xna.Framework.Content.ContentTypeReaderManager.GetTypeReader(Type targetType) at Microsoft.Xna.Framework.Content.ReflectiveReaderMemberHelper..ctor(ContentTypeReaderManager manager, FieldInfo fieldInfo, PropertyInfo propertyInfo, Type memberType, Boolean canWrite) at Microsoft.Xna.Framework.Content.ReflectiveReaderMemberHelper.TryCreate(ContentTypeReaderManager manager, Type declaringType, FieldInfo fieldInfo) at Microsoft.Xna.Framework.Content.ReflectiveReader1.Initialize(ContentTypeReaderManager manager) at Microsoft.Xna.Framework.Content.ContentTypeReaderManager.ReadTypeManifest(Int32 typeCount, ContentReader contentReader) at Microsoft.Xna.Framework.Content.ContentReader.ReadHeader() at Microsoft.Xna.Framework.Content.ContentReader.ReadAsset[T]() at Microsoft.Xna.Framework.Content.ContentManager.ReadAsset[T](String assetName, Action1 recordDisposableObject) at Microsoft.Xna.Framework.Content.ContentManager.Load[T](String assetName) at TiledTest.Game1.LoadContent() in C:\My Documents\Dropbox\Visual Studio Projects\TiledTest\TiledTest\TiledTest\Game1.cs:line 51 at Microsoft.Xna.Framework.Game.Initialize() at TiledTest.Game1.Initialize() in C:\My Documents\Dropbox\Visual Studio Projects\TiledTest\TiledTest\TiledTest\Game1.cs:line 39 at Microsoft.Xna.Framework.Game.RunGame(Boolean useBlockingRun) at Microsoft.Xna.Framework.Game.Run() at TiledTest.Program.Main(String[] args) in C:\My Documents\Dropbox\Visual Studio Projects\TiledTest\TiledTest\TiledTest\Program.cs:line 15 This is all incredibly frustrating as the demo doesn't appear to have any special linking properties. The TiledLib I am utilizing is from Nick Gravelyn, and can be found here: https://bitbucket.org/nickgravelyn/tiledlib. The demo it comes with works fine, and yet in recreating I always run into this error.