How to fix the "Warning: waitCursor stack empty" error @ Advanced Skeleton

In previous chapters we talked about how I kept on improving my previous model, which Advanced Skeleton was using as reference, and how said changes messed up the weights, rendering the walking cycle I had made completely useless.

Above: uselessness

After spending ages trying to fix it unsuccessfully, I decided to re-do the rigging from scratch... also because the referenced file is not rendering the hair I created and I am fed up wondering Maya mysterious ways, so I took a file that renders the hair perfectly and started rigging again.  Then... while on that, I faced this brand new error:

... followed by our friendly  "Warning: waitCursor stack empty"

This, after hitting the "Adv" button to generate the other half of the rig. I noticed the other expected half wasn't created, but the handlers were... then I remembered I did some changes previous to readjusting the joints:  my model was facing the opposite direction than the  generated biped, and since I've got way too much elements on it, I opted for rotating the biped instead of the mesh, by 180 degrees. Happens the "Adv" button that generates the rig is quite rigid, and it was actually creating the other half, just above my previous rotated half so I could not notice it. So basically if you move/rotate the skeleton at the Root to fit your model, you will get these errors. Also, if your main joints and bones (the ones of the spine) are not exactly zeroed at the x axis, you can get duplicated bones that will be hard to handle later, so... to get rid of these errors, make sure your skeleton is zeroed at rotation and translation values at the Root, then hit "Adv". This should generate your rig without problems. Once generated, just click your main controller (the large circle at the floor) and reposition it to match your mesh.