diff --git a/PortraitBuilder/Engine/Loader.cs b/PortraitBuilder/Engine/Loader.cs
index ccf0850..a0c4a3a 100644
--- a/PortraitBuilder/Engine/Loader.cs
+++ b/PortraitBuilder/Engine/Loader.cs
@@ -99,7 +99,7 @@ public List<DLC> LoadDLCs(Boolean clean) {
 		}
 
 		public List<DLC> LoadDLCs() {
-			string dlcFolder = user.GameDir + "dlc" + Path.DirectorySeparatorChar;
+			string dlcFolder = Path.Combine(user.GameDir,"dlc");
 			logger.Info("Loading DLCs from " + dlcFolder);
 			List<DLC> dlcs = dlcReader.ParseFolder(dlcFolder);
 
@@ -120,11 +120,11 @@ private void UnzipDLCs(List<DLC> dlcs) {
 			FastZip fastZip = new FastZip();
 			foreach (DLC dlc in dlcs) {
 				string dlcCode = dlc.DLCFile.Replace(".dlc", "");
-				string newDlcAbsolutePath = user.DlcDir + dlcCode + Path.DirectorySeparatorChar;
+				string newDlcAbsolutePath = Path.Combine(user.DlcDir, dlcCode);
 				if (!Directory.Exists(newDlcAbsolutePath)) {
 					logger.Info(string.Format("Extracting {0} to {1}", dlc.Name, newDlcAbsolutePath));
 					// Filter only portraits files, to gain speed/space
-					string fileFilter = @"interface;gfx/characters";
+					string fileFilter = @"interface;gfx"+Path.DirectorySeparatorChar+"characters";
 					fastZip.ExtractZip(dlc.AbsolutePath, newDlcAbsolutePath, fileFilter);
 
 					// In any case, create the directory, so that it is ignored for next load.
diff --git a/PortraitBuilder/Parser/DLCReader.cs b/PortraitBuilder/Parser/DLCReader.cs
index a4db03b..ca91159 100644
--- a/PortraitBuilder/Parser/DLCReader.cs
+++ b/PortraitBuilder/Parser/DLCReader.cs
@@ -23,9 +23,9 @@ public List<DLC> ParseFolder(string folder) {
 				foreach (FileInfo dlcFile in dlcFiles) {
 					DLC dlc = Parse(dlcFile.FullName);
 					if (dlc != null && dlc.Archive != null) {
-						// Note: path will be overriden when extracting the archive
-						dlc.AbsolutePath = folder + dlc.Archive.Replace("dlc/", "");
-						dlcs.Add(dlc);
+                        // Note: path will be overriden when extracting the archive
+                        dlc.AbsolutePath = Path.Combine(folder, dlc.Archive.Substring("dlc".Length +1)); // Remove "dlc/" from path
+                        dlcs.Add(dlc);
 					}
 				}
 			} else {
diff --git a/PortraitBuilder/Parser/ModReader.cs b/PortraitBuilder/Parser/ModReader.cs
index b0765e1..4b92f96 100644
--- a/PortraitBuilder/Parser/ModReader.cs
+++ b/PortraitBuilder/Parser/ModReader.cs
@@ -29,7 +29,7 @@ public List<Mod> ParseFolder(string folder) {
 					try {
 						Mod mod = Parse(modFile.FullName);
 						if (mod != null && mod.Path != null) {
-							mod.AbsolutePath = folder + Path.DirectorySeparatorChar + mod.Path.Replace("mod/", "");
+                            mod.AbsolutePath = Path.Combine(folder, mod.Path.Substring("mod".Length + 1)); // Remove "mod/" from path
 							mods.Add(mod);
 						}
 					} catch (Exception e) {
diff --git a/PortraitBuilder/Parser/PortraitReader.cs b/PortraitBuilder/Parser/PortraitReader.cs
index cf93393..8b8e900 100644
--- a/PortraitBuilder/Parser/PortraitReader.cs
+++ b/PortraitBuilder/Parser/PortraitReader.cs
@@ -36,20 +36,20 @@ public PortraitData Parse(string dir) {
 			try {
 				List<string> fileNames = new List<string>();
 
-				if (Directory.Exists(dir + @"\interface\")) {
-					fileNames.AddRange(Directory.GetFiles(dir + @"\interface\", "*.gfx"));
+				if (Directory.Exists(Path.Combine(dir, "interface"))) {
+					fileNames.AddRange(Directory.GetFiles(Path.Combine(dir, "interface"), "*.gfx"));
 				}
 				// interface/portraits seems to be loaded after interface/, and override (cf byzantinegfx)
-				if (Directory.Exists(dir + @"\interface\portraits\")) {
-					fileNames.AddRange(Directory.GetFiles(dir + @"\interface\portraits\", "*.gfx"));
+				if (Directory.Exists(Path.Combine(dir, "interface", "portraits"))) {
+					fileNames.AddRange(Directory.GetFiles(Path.Combine(dir, "interface", "portraits"), "*.gfx"));
 				}
 
 				foreach (string fileName in fileNames) {
 					Parse(fileName, data);
 				}
 
-				if (Directory.Exists(dir + @"\interface\portrait_offsets\")) {
-					string[] offsetFileNames = Directory.GetFiles(dir + @"\interface\portrait_offsets\", "*.txt");
+				if (Directory.Exists(Path.Combine(dir, "interface", "portrait_offsets"))) {
+					string[] offsetFileNames = Directory.GetFiles(Path.Combine(dir, "interface", "portrait_offsets"), "*.txt");
 					foreach (string offsetFileName in offsetFileNames) {
 						Dictionary<string, Point> offsets = portraitOffsetReader.Parse(offsetFileName);
 						data.Offsets = data.Offsets.Concat(offsets).GroupBy(d => d.Key).ToDictionary(d => d.Key, d => d.First().Value);
diff --git a/PortraitBuilder/Program.cs b/PortraitBuilder/Program.cs
index 767ee8e..5f4a7c9 100644
--- a/PortraitBuilder/Program.cs
+++ b/PortraitBuilder/Program.cs
@@ -35,8 +35,8 @@ static void Main(string[] args) {
 
 			Application.ApplicationExit += new EventHandler(onExitApplication);
 
-			if (!Directory.Exists("dlc/"))
-				Directory.CreateDirectory("dlc/");
+			if (!Directory.Exists("dlc"))
+				Directory.CreateDirectory("dlc");
 
 			if (!File.Exists("gamedir")) {
 				string dir = null;
diff --git a/PortraitBuilder/UI/PortraitBuilderForm.cs b/PortraitBuilder/UI/PortraitBuilderForm.cs
index 9b32c91..888fb37 100644
--- a/PortraitBuilder/UI/PortraitBuilderForm.cs
+++ b/PortraitBuilder/UI/PortraitBuilderForm.cs
@@ -226,18 +226,33 @@ private string readGameDir() {
 		/// Read userdir.txt in Steam directory for the path to mod dir, or default to pre-defined location
 		/// </summary>
 		private string readModDir(string gameDir) {
-			string modDir = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), "Paradox Interactive", "Crusader Kings II") + Path.DirectorySeparatorChar;
+			string userDir = getDefaultUserDir();
 			string userdirFilePath = Path.Combine(gameDir, "userdir.txt");
 			if(File.Exists(userdirFilePath)){
 				logger.Info("Reading userdir.txt to determine the mod directory.");
 				Stream stream = new FileStream(userdirFilePath, FileMode.Open);
 				StreamReader reader = new StreamReader(stream, Encoding.Default);
-				modDir = reader.ReadLine() + Path.DirectorySeparatorChar;
-				logger.Info("Found userdir.txt with path: " + modDir);
-			}
-			modDir = Path.Combine(modDir, "mod");
-			return modDir;
-		}
+                userDir = reader.ReadLine() + Path.DirectorySeparatorChar;
+				logger.Info("Found userdir.txt with path: " + userDir);
+			}
+			return Path.Combine(userDir, "mod");
+        }
+
+        private string getDefaultUserDir() {
+            string userDir = null;
+            PlatformID os = System.Environment.OSVersion.Platform;
+            if (os == PlatformID.Win32NT || os == PlatformID.Win32Windows) {
+                userDir = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), "Paradox Interactive", "Crusader Kings II");
+            } else if (os == PlatformID.MacOSX || (int) os == 128) {
+                // Environment.SpecialFolder.MyDocuments does not add /Documents/ on Mac
+                userDir = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), "Documents", "Paradox Interactive", "Crusader Kings II");
+            } else if (os == PlatformID.Unix) {
+                userDir = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), ".paradoxinteractive", "Crusader Kings II");
+            } else {
+                logger.Error("Unkown platformID " + os);
+            }
+            return userDir;
+        }
 
 		/// <summary>
 		/// Entry point for re-drawing based on updated portrait.
diff --git a/PortraitBuilder/app.config b/PortraitBuilder/app.config
index 0eee32f..93b27b9 100644
--- a/PortraitBuilder/app.config
+++ b/PortraitBuilder/app.config
@@ -33,7 +33,7 @@
   </log4net>
   <runtime>
     <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
-      <probing privatePath="lib;libs" xmlns="" />
+      <probing privatePath="lib" />
     </assemblyBinding>
   </runtime>
   <startup useLegacyV2RuntimeActivationPolicy="true">