E18 on Beko B3WFU48215WW ES indicates that the spin cycle has not started due to imbalance. Check how the load is distributed and whether the load is too small.
A single item can throw the load off balance
The manufacturer documentation directs you to check the laundry and distribute it manually. With the program stopped and the door unlocked, untangle the garments and redistribute the contents. An absorbent item can concentrate the weight when it gets wet, even if it takes up little space when dry.
If the load is insufficient, add only compatible garments when the manual and the program capacity allow it. Do not compensate by adding water by hand or by packing in more laundry than the machine can handle.
When to repeat the spin cycle
Once the distribution has been corrected and you have confirmed that the water has drained, use the spin cycle compatible with those fabrics. Increasing the speed does not correct an uneven load.
If the warning returns with suitable loads, record the program, garments, and vibration, and request service. Laundry amount and distribution develops those criteria. Distinguish an E18 observed now from a record of a previous load in the history.
This interpretation is not universal for Beko: confirm the same meaning in the manual for another series.