Thanks, that did it! Well, it runs, but it doesn’t work well:
...
[2,    80] loss: 0.474
[2,    81] loss: 0.951
[2,    82] loss: 0.837
[2,    83] loss: 0.476
[2,    84] loss: 0.828
[2,    85] loss: 0.725
[2,    86] loss: 0.717
[2,    87] loss: 0.830
Finished Training

My reasoning was, since I have two classes and truth values of 0 or 1 for each image, the net should have one output that is either closer to 0 or 1. Now that the net’s output is a vector with two entries, do the truth values also have to have two entries per image? I.e. (0,1) or (1,0)?