The one hole in the photo is open because thats where the middle spray arm manifold goes into when you push your upper back inside the dishwasher.
It more likely an issue with either the chopper screen blade broken or the motor.
Here's the repair manual for your model:
Page 17 Read 1-4 where it says this:
SERVICING COMPONENTS INSIDE THE WASH TUB
Removing the Inner Feed Tube and
Lower Spray Arm
Then on Page 21 it starts to get into detail of how to access the rest where it says this:
Accessing Components of the Sump Assembly
It shows how to get access to the chopper screen.
Here's the wash motor assembly for your model:
Whirlpool W10239404 Circulation Motor - AppliancePartsPros.com
Here's the sump/wash motor assembly for your model you can order: Manufacturer's Number: W10237169
Let us know what you find.