For unknown reasons "Save All" doesn't save the vsprops files.
diff --git a/PCbuild9/pyproject.vsprops b/PCbuild9/pyproject.vsprops
index e1c9023..76a7733 100644
--- a/PCbuild9/pyproject.vsprops
+++ b/PCbuild9/pyproject.vsprops
@@ -11,7 +11,7 @@
 		Optimization="2"
 		InlineFunctionExpansion="1"
 		AdditionalIncludeDirectories="..\Include; ..\PC"
-		PreprocessorDefinitions="_CRT_SECURE_NO_DEPRECATE"
+		PreprocessorDefinitions="WIN32;_CRT_SECURE_NO_DEPRECATE"
 		StringPooling="true"
 		ExceptionHandling="0"
 		RuntimeLibrary="0"