If you're using the DISABLE_TALKIE define to save memory, the spoken error messages from the "What is it saying?" page will be replaced with beeps. This page will let you figure out what those beeps mean. Once you figure out which one is is, go to the What is it saying? page to find out what to do about it.
Try clicking on each line to hear what it sounds like.
That last one is not actually an error message, it's the sounds you hear if you use the "beep" command, and is also the notes from "Close Encounters of the 3rd Kind".
All of the beep codes above were composed with the same number of notes as the syllables in the error message. If you can sing the error code to the beep codes, then maybe you can figure out what the problem is without consulting this page. This video might help visualize things as well: https://www.youtube.com/watch?v=bVPDhBp1l9c