A solution for the error 'The security header is not valid' in OpenCart when using PayPal Express Checkout.
PHP 5.4 introduced traits. Traits are in many ways like code-assisted copy and paste. They are ways to mix code into a class without inheritance. But what are they good for? When should they be used?
When you install 3D Studio Max 2010, it does not automatically install any Particle Flow Presets. They are available in the Samples DVD that ships with Max. Here is how to install them.