Plots are not displayed in Jupyter

I am working on the Wk-2 assignment: Logistic Regression with a Neural Network mindset. At the end of the notebook, there is code block for plotting the cost function. When I execute it, the plot is not displayed. How to fix this issue?

You mean the last cell, “Test with your own image”?, if so, try Kernel → Restart and then run all. But make sure you uploaded your own image into the images.

I have reloaded the complete page. Now, it works. Thank you.