Samsung WF50A8600 front-load washer will not drain or stops with water inside

The checks in more detail

and the code points straight at the drain path: the filter, the hose, the standpipe and the pump. Start with the filter. Unplug the washer. Put a shallow dish and towels under the small panel at the lower front, open it and look for the small drain hose and the filter cap; pull the drain hose plug to let water run into the dish a little at a time, then unscrew the filter slowly.

Clear coins, lint, hair and small clothing from the filter and look into the chamber for anything caught round the pump impeller; the impeller should turn freely. Refit the filter firmly, because a loose cap leaks. Replace the panel. Then the hose and standpipe. Pull the washer forward and check the drain hose for kinks, a crushed section or a bend that is lower than the standpipe; the hose should loop high before dropping into the pipe. Check that the standpipe is not blocked by running water into it.

Also look at detergent: too much high-efficiency detergent produces suds that slow draining and can trigger a suds routine, so run a rinse if the drum is foamy. After the water is out, restart a drain and spin to test. If the filter, hose and standpipe are clear and the code returns, or the pump hums without moving water, the pump or its wiring is the likely fault and a technician should check it. Quote WF50A8600AE and the serial number.