Inglis dishwasher not draining - trouble removing filter

My inglis dishwasher model 1ku58660 stopped working mid cycle earlier this week. I noticed because the rinse only light was flashing but that wasn’t the cycle I had chosen.also, nothing was happening inside the dishwasher anymore and none of the buttons worked.
I opened the door and found a pool of water at the bottom. I turned off the breaker, emptied it manually and have been trying to remove the filter to see if it’s clogged.
I got the arms off but now I’m facing a nut on a black spinning disc and every time I try to turn the nut, the disc spins (both directions). I try to hold it but the nut is too tight.

What else can I do before I call a repair service?

Is this your machine?

I’d suspect the computer if nothing works.