Problems with Assets/Standard Assets/Effects/ImageEffects

Hi, I encountered a few problems with the Standard Assets, as shown below:

Assets/Standard Assets/Effects/ImageEffects/Scripts/ColorCorrectionCurves.cs(8,42): error CS0246: The type or namespace name 'PostEffectsBase' could not be found (are you missing a using directive or an assembly reference?)

Assets/Standard Assets/Effects/ImageEffects/Scripts/Antialiasing.cs(20,33): error CS0246: The type or namespace name 'PostEffectsBase' could not be found (are you missing a using directive or an assembly reference?)

Assets/Standard Assets/Effects/ImageEffects/Scripts/Antialiasing.cs(86,30): error CS0115: 'Antialiasing.CheckResources()': no suitable method found to override

Assets/Standard Assets/Effects/ImageEffects/Scripts/ColorCorrectionCurves.cs(53,18): warning CS0109: The member 'ColorCorrectionCurves.Start()' does not hide an accessible member. The new keyword is not required.

Assets/Standard Assets/Effects/ImageEffects/Scripts/ColorCorrectionCurves.cs(62,30): error CS0115: 'ColorCorrectionCurves.CheckResources()': no suitable method found to override

I am completely new to Unity and would sincerely appreciate it if anyone can help me out!