Error in vl_simplenn_tidy (line 45)

[Farisya33]

This error comes when I try using model that I've set up instead of imagenet-vgg-f.mat. The imagenet-vgg-f.mat works just fine, but when I test with my model, it came out like this:

Reference to non-existent field 'layers'.

Error in vl_simplenn_tidy (line 45)
for l = 1:numel(net.layers)

Can someone help me. I'm using MatConvNet25, matlabR2019b, c++