I haven’t used the Standard Assets FP Controller prefab in quite a while, but I do not remember any scripts attached to it called PlatformInputController.js. Double check you added the correct prefab to your scene and also jump into the code on line 5 (see error message) and check for errors.
Actually the new Unity5 does have that in the script for the controllers and the cross platform input is what it sounds like, to use on different platforms like Android, Windows, Mac, etc. You are going to have to learn to make working player controller scripts if you dont want some of the bloatware that comes with the rather not so great latest FPS and TPS default "standard assets characters, which frankly when compared to the ones they had in 4.6 Seriously suck on many levels,
mybe script has corupted,and missing '}' at the end of script file open in MonoDevelop or other ide as u want and put the '}' at the end
– Leon_SFS