Avansomeren is referring to the "I want to create a web application" helper task featured on the help page.
It is the one repo'd here.
If you look at the code for step (I think it is step #10?) where you have to copy and paste in a block of code that begins
from flask import Flask, request, url_for
you'll see the function 'hello_person()' is defined but the next line with the return command is not indented. I didn't try running it myself, but it does look wrong.
def hello_person():
return """
<p>Who do you want me to say "Hi" to?</p>
<form method="POST" action="%s"><input name="person" /><input type="submit" value="Go!" /></form>
""" % (url_for('greet'),)
I happen to be using Google Chrome browser at the moment, and so I don't know if that is related to his experience having the indenting be an issue on Chromebook.
Looks like the 'greet()' function has the same issue?