Most commonly the OE error appears in LG dishwashers when there is a drain issue. It means that water is not draining out of the system as it should be. If that is the case, please, check the drain hose for blockages, twists and constrictions. Also, there may be a problem in the drain pump. Make sure it is not blocked: more often than not, large pieces of debris and foreign objects get into it and block it. If the pump is all right, make sure that the float switch is not blocked.

Here is some detail on fixing the oe error:

If your LG dishwasher displays the OE error code, there is definitely a drain problem. In other words, it gets too slow to drain or fails to drain at all. Most likely, the drain house has gotten clogged, or there is a problem with the drain pump.

Not infrequently, the drain hose gets looped and/or kinked. Check it and ensure it is positioned properly.

• Remove any bends and/or kinks and ensure the hose is stretched out.
• Be sure that it is not clogged: there may be food particles blocking it.
• Check the wall drain for clogs and blocks.
• Install a HIGH DRAIN LOOPor AIR GAP. You can choose not to use these, but if you don’t, water may accumulate in the base tray.
• If you see any damage in the drain hose, replace it.