MatPlotLib output stuck loading when run

Problem description:

This code is input into a repl python file:

import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 4])

plt.ylabel(‘some numbers’)

Which should show an output of a graph, however we just get a black box with a blue circle spinning and the code is stuck running for all students in the class. I have tried it on my teacher account and it seems to work fine.

Expected behavior:

Graph displayed in the output box.

Actual behavior:

Output display box stuck as black screen, and blue circle spinning in the middle.

Steps to reproduce:

Input above code, and click run.

Bug appears at this link:


Google Chrome, Chrome OS, Chromebook Asus C204M

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Hi there, do the students’ devices have any browser extensions installed? Does disabling them help?

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this may be due to network restrictions. Make sure * is allowed so that the VNC session can be hosted

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