Matlab 2012b error in neural network Non-singleton dimensions of the two input arrays must match each other.

i wrote my script to split dataset into XTrain, YTrain, XTest and YTest.

the dimensions are equal for all matrix example sample size e.g. size is following for above matrix

XTrain = 25 X 256 (double)

YTrain = 11 X 256 (double)

XTest = 25 X 256 (double)

YTest = 25 X (double)

my code is following

setdemorandstream(491218382);
   net = patternnet(10);
   [net,tr] = train(net, XTrain, YTrain);
   nntraintool;
   plotperform(tr);
   testY = net(XTest);
   

The training part is good but when the last line is called the error is thrown instantly

Error using bsxfun

Non-singleton dimensions of the two input arrays must match each other.

I have already searched and found many explanations but i can't understand them specialy the solution mentioned in this Link

Could any body please explain the core anatomy behind this problem in the context of my spliting of dataset