Please help as I have landed into a trouble with my flask server for pset8/mashup. Per the spec within mashup/ I execute pip install --user -r requirements.txt and then in a terminal window I execute export API_KEY=value (value from credentials in my console). I have made two API keys though I use one of them. Then in mashup/ I execute flask run and then in another terminal within mashup/ I execute phpliteadmin mashup.db. After this when I go to CS50 IDE>Web Server I get a webpage saying "no application seems to be running here". Flask was showing the following messges : * Serving Flask app "application" * Forcing debug mode on * Running on (Press CTRL+C to quit) * Restarting with stat * Debugger is active! * Debugger PIN: 270-621-200

"Running on (Press CTRL+C to quit)" seems relevant as it is serving PORT 5000 which I guess should be 8080 for my application to run. But I am too naive to do this. So, plse tell me how to resolve this issue to get my CS50 IDE server run my application.


Change the call from flask run to flask run --host= --port=8080 and it should work, as per this reddit post.

  • Thanks, buddy, you are a true genius! I was almost clueless how my server would work but now this is resolved. In fact, I did notice that David used the above code to run flask in some of the applications of week8 and week9 lectures but didn't pay attention then. Anyway, thanks again.
    – sk.76
    Aug 2 '17 at 11:19
  • I have the same error but my output says: * Running on ide50-chrisdziewa1.c9users.io:5000 I tried the above fix and it still isn't working. Any ideas? It was working fine yesterday.
    – razzdango
    Aug 2 '17 at 23:27
  • @razzdango According to the cs50 status page this was fixed with a new IDE version (update50). Aug 3 '17 at 11:34
  • @razzdango do u execute update50 before running flask?
    – sk.76
    Aug 3 '17 at 11:43

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .