SystemAction.get method not found

Thank you for the suggestions. Alas, the problem persists.

I renamed all of the following folders:
	 .nbi in the C:\Users\<username> folder,

	 .netbeans in the C:\Users\<username> folder,

	 8.2 in the C:\Users\<username>\AppData\Local\Netbeans\Cache folder, and

	 8.2 in the C:\Users\<username>\AppData\Roaming\Netbeans folder,


and performed a Clean and Build on the project (which rebuilt my required module projects as well).
All of the System.get(...) error messages persist (7 errors in all).

Further suggestions most welcome.