Solved by KFrank in post #2 
              
              
                Hi Luke! 

By the time you get to fc1 – where the error is occurring – your images 
are no longer of the same size as when passed into forward(). 

Conv2d changes (reduces) the size of your image. 

MaxPool2d also reduces the size of your image. 

In forward(), print out the shape of x (initially yo…