Invalid header files

I am an experienced programmer, but new to the Arduino.

I wrote (actually copied a simple blink internal led) sketch. It compiled and uploaded to the Arduino and runs properly.

But I am getting this error/warning message:

" Invalid library found in C:\Users\Owner\Documents\Arduino\libraries\sketch_apr12a: no headers files (.h) found in C:\Users\Owner\Documents\Arduino\libraries\sketch_apr12a "

I did a global file search of the hard drive and located all files with the file extension .H and found what looks like a couple of hundred Arduino header files but they are not located in the folder/directory shown in the error/warning message.

I would appreciate any help to fix this problem.

Your sketch should not go in the libraries folder

C:\Users\Owner\Documents\Arduino
--> sketch
      --> sketch.ino
--> other sketch
      --> other sketch.ino
--> libraries
      --> 3rd party library
      --> other 3rd party library

Thanks, perfect.