Errors with Image Effects

I've been using the trial verison of Unity Pro, and the image effects, but now any effect I apply to the main camera gives me this (for example on Sunshafts):

NullReferenceException: Object reference not set to an instance of an object SunShafts.OnRenderImage (UnityEngine.RenderTexture source, UnityEngine.RenderTexture destination) (at Assets/Standard Assets/Image Effects (Pro Only)/SunShafts.js:79)

I also get these for Antialiasing as Post Effect:

Graphics.Blit: material is null UnityEngine.Graphics:Blit(Texture, RenderTexture, Material) AntialiasingAsPostEffect:OnRenderImage(RenderTexture, RenderTexture) (at Assets/Standard Assets/Image Effects (Pro Only)/AntialiasingAsPostEffect.js:77)

Missing shader in Main Camera (AntialiasingAsPostEffect) UnityEngine.Debug:Log(Object) PostEffectsBase:CheckShaderAndCreateMaterial(Shader, Material) (at Assets/Standard Assets/Image Effects (Pro Only)/PostEffectsBase.js:13) AntialiasingAsPostEffect:CreateMaterials() (at Assets/Standard Assets/Image Effects (Pro Only)/AntialiasingAsPostEffect.js:37) AntialiasingAsPostEffect:OnRenderImage(RenderTexture, RenderTexture) (at Assets/Standard Assets/Image Effects (Pro Only)/AntialiasingAsPostEffect.js:51)

The effects worked fine when I first imported the package, but somehow this started happening. I should have all the shaders etc. for them to work, and I could get SSAOEffect to work by dragging the right shader to the right place in the inspector, but color correction, antialiasing etc. don't have those slots in the inspector.

Any help appreciated :)