`[MPSCNNConvolution encode...] Error: destination may not be nil'

I try to run mlmodel prediction and I get below error:

/Library/Caches/com.apple.xbs/Sources/MetalImage/MetalImage-124.0.29/MPSNeuralNetwork/Filters/MPSCNNKernel.mm:752: failed assertion `[MPSCNNConvolution encode...] Error: destination may not be nil.

I use IOS 14 and implement the same method. I attach the screen shot of the code where error occurs:
Appreciate your advice