UNQ_C3` wasn't found in code

I tried to submit the assignment on segmantation using u-nets. However, I am getting this error after submission and not getting any points-“Comment line with index: UNQ_C3 wasn’t found in code”. Any suggestions?

Did you modify any of the comments in the cell that has the “UNQ_C3” label?

Right, the error message seems pretty clear, doesn’t it? Notice that the other graded cells have comments that include “tags” like UNQ_C? … It’s a bad idea to modify those. If you want to get a clean copy of the notebook and figure out what the original templates look like, there is a topic about that on the FAQ Thread.