Why do my "Standard" unedited First Person and 3rd Person Prefab Controller scripts come up with the Compiler error messages?

Tried reloading scripts, and even Uninstalled Unity and reloaded. How can I just reload/install the PREFABS and get their associated scripts to show up correctly?

you can simply delete the sample asset folder in your project files and add the asset with the character controller again. Please explain what error exactly this is

There is no Sample Asset Folder in Original Unity. These are the default Standard Assets Character Controllers and Scripts that you select when starting a New Project. The Scripts for the First Person Controller prefab are the Original ones from Unity. They are not changed from original condition.
I just had it happen again on the Project that was working yesterday.
I made a new Project and only added the Character Controllers and terrain, sky stuff. SAVED the project and Opened the Bad Project. Deleted the entire Standard Assets Folder and saved the project. Closed Unity. Copy and Pasted the Standard Assets Folder from the Good Project to the Bad Project and opened Unity.

The Character Controllers still have the Following in the Inspector under the Third Person and First Person Controller “The associated script can not be loaded. Please fix any compile errors and assign a valid script.”
That notice is under the Character Motor, Mouse Look, and FPSInput (Script) sections as well as the Third Person Controller and Camera.

This is exhausting having to Begin a New Project and move all my Assets to the New Project, just because it has a good Character Controller.

What is the ANSWER??