Solved by b02202050 in post #2 
              
              
                As in the PyTorch document, 
 [image] 
torch.bmm should be used when both input are batched matrixes. 
But it seems like you are doing multiplication with a batch of vector by a constant matrix. 
If you really want to use bmm, you can make both of your inputs be the right format like the following. 
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