The LG error code OE simply means “the pump is blocked”. Presumably the water isn’t being emptied properly, but as with all error codes it is possible that there is a cause other than the error code explanation.
Basically this error means that the washing machine thinks the water isn’t pumping out. That’s probably the case, and a pump, or filter blockage is the most common cause. However, this error code could be caused by other faults such as a faulty pump, or even a blockage in the drain hose, or somewhere else in the pressure system etc.
Bizarrely, according to LG, “if the unit is not levelled properly, it will not drain properly. The front of the unit cannot be higher than the back or vice versa”. However, it probably doesn’t mean it would stop it draining the water at all, I’m assuming it just means there might be a little bit of water left in the machine.
If you have the OE error and you can see that there is a lot of water still inside the machine try this article washing machine won’t empty water. If it seems like the water has been pumped away then it could be that a pressure system fault has stopped the machine getting the signal that the water has gone and it’s ok to spin. This is more involved than dealing with not emptying though so unless you fully understand the way it works get an engineer – pressure system faults