Make the Resources directory if needed.
diff --git a/Mac/scripts/buildappbundle.py b/Mac/scripts/buildappbundle.py
index 93ef14b..49a1513 100755
--- a/Mac/scripts/buildappbundle.py
+++ b/Mac/scripts/buildappbundle.py
@@ -101,6 +101,8 @@
 	#
 	if resources:
 		resdir = os.path.join(contents, 'Resources')
+		if not os.path.isdir(resdir):
+			os.mkdir(resdir)
 		for src in resources:
 			dst = os.path.join(resdir, os.path.split(src)[1])
 			if os.path.isdir(src):