Flask isn't recognising connections from other clients
you need to configure your firewall on your server/workstation to allow connections on port 5000.  setting the ip to 0.0.0.0 allows connections to your machine but only if you have the port open.  also, you will need to connect via the ip of your machine and not localhost since localhost will only work from the machine where the server is running.
I have an apache server setup on a Pi, and i'm trying to learn Flask. I set it up so that The 'view' from the index '/' returns "hello world". then i ran my main program. nothing happens from the browser on the PC i'm SSH'ing from,I just get an error saying , but when i used the Pi directly and went to http:localhost:5000/ i got a response.I read about setting Host to '0.0.0.0' but that didnt help. how can i get my Flask to accept all connections? does it make a difference that I have an 'index.html' in '/'?