First try unplugging the machine for a few minutes and then retry a cycle. If you still get the LE error:
The Hall sensor (part number 6501KW2001A) has failed. The hall sensor is rather easy to replace, and is covered by a seven year part warranty (in the US). Take the back cover off. Take the big nut off and remove the motor rotor. Remove the bolts holding the motor windings. Remove the electric plug on the sensor and unclip it from the motor winding. Snap new sensor on and reassemble. Usually
takes under a half hour. On a difficulty scale of 1 - 10, it might rate a 4. This should be a Fix-Ya for your machine, and at basically no cost!
In the US, find a service provider
using your zip code at http://us.lgservice.com/index_b2c.jsp
or call LG