Conan_Usage.md

@@ -28,6 +28,8 @@ cd <build directory>
 conan install --build=missing -s compiler="Visual Studio" -s compiler.version=15 <relative path to source directory>
 cmake <relative path to source directory>
 ```
+* **Troubleshooting:**
+ * Windows 8.1 SDK in the Visual Studio 2017 Installer apparently has to be ticked otherwise an error with missing ctypes.h occurs during building glew
 
 ### Apple