The code of Chp 6 don't work ---- RuntimeError: mat1 dim 1 must match mat2 dim 0

[yu-cheng-kuo-28]

The "IMDB with and without pretrained Embeddings.ipynb" didn't work, I got the error: RuntimeError: mat1 dim 1 must match mat2 dim 0. I've googled the info about this error yet couldn't fix it. I would like to know why. Much appreciation.
https://i.imgur.com/SSd0hXp.png