Hi, welcome to Just answer
Please tell me its complete model number
and how old is it ?
WMA52P aprox. 9 years old
Door interlock assembly is bad and will need replacement
You can buy it from here
a new one will cost you £9
are you looking to replace it yourself ?
Please check this Video
and follow the instructions to replace it
looking at the age of the unit I would recommend to replace both latch mechanism and the interlock