Hi! For homework C3_W2_RecSysNN_Assignment, i kept getting errors for the orginal codes not the part we need to write, as attached. does anyone know how to solve this issue? thank you in advance!
First question:
When you opened the notebook, did you first run all of the cells starting from the top?
yes- tried to run the cells from the begining the error is still there. Good news is im actually able to submit the assignment 100 passed with this error 
That’s good, I’ll check further and see if the notebook has been updated recently.
No, the notebook hasn’t been updated, and I was able to run all the cells without errors.
Did you modify any of the data in the cell in Section 5.1 that creates the “user_vec” array?
Also, maybe try using “Kernel->Restart and clear output” and then run all of the cells again. Then inspect the results of every cell looking for any error messages.