dE, dE1, dE2, and dC1 indicate a lack of close confirmation in the Samsung documentation consulted. A door that seems latched may still not be locked enough to start.
The Samsung chart groups these door signals. Check the reference before adding other aliases; dC has a model-specific ambiguity.
Visible check of the latch
If the drum is stopped and the latch allows the door to open, check whether clothing is caught in it or a load is pressing against the door from inside. Close it gently. Look for damage to the latch or handle, but do not remove the lock or bypass it.
If the fault appears midway through the program with water or high temperature, the inability to open may be an additional protection. Do not pull on the door to repeat the outside check.
If the lock area is clear and the message returns after the recovery described in the manual, request service. Say whether it never started, whether water entered, or whether it stopped during the wash: that information narrows down which state the technician should inspect.
Do not substitute an audible click for the manual's confirmation: mechanical closure and electronic cycle authorization are separate checks.