I can't upload a new build using Xcode7 or Application Loader. It gets stuck on "Verifying assest with Itunes Store", and after a couple of minutes i get the error "Client unable to connect to server (check UDP port and firewall) (15)".
I tried uploading a new build with the Xcode6.4, and it worked. Did they change some port? Any way to fix it? My Mac have the firewall disabled.
Yesterday somehow i could upload a build, i was messing around with the router and other things, but i'm not sure what did the trick.
I was having the very same issue in my company's network because there was a firewall. Contacted with the system admin and we have monitored the process, seen that it was trying to connect over UDP 33001 port but failing, then passing to alternatives. So we have allowed UDP 33001 port, I was able to upload successfully.
The thing is that these numbers might change in the future, as it (most probably) happened when Xcode has changed from 6.4 to 7.0. Take a look at this comment: https://stackoverflow.com/a/6178286/705982
There you will see the ports Application Loader uses. If you can't monitor the upload process, then try to create allow rules for one or some of these ports. You should be good to go.