If the machine senses that the wash load is not balanced, it will make several attempts to adjust the wash load. If it is unable to do that, it will abort the spin cycle and skip straight to drain part of the cycle. This is designed to protect your machine from harmful vibration.
The machine will not be able to balance one single item or just a very small load. It is more economical to wash a full load so make sure that you have a good size load in the drum.