If you clear the filter, reassemble the machine, and it still won't drain, the problem is likely deeper. You may have a failed drain pump (the motor has burnt out) or a blocked internal drain hose that requires dismantling the machine's chassis. At that point, a service technician is required.
Disconnect the washing machine from the power outlet. You are working near water and electricity. blocked filter washing machine
The #1 cause of blocked filters is loose change and tissues left in pockets. If you clear the filter, reassemble the machine,