I tried to upload media via the Prism app and it froze, didn't upload or I received a Server Error message.
Media files generally take a lot longer to upload, which is why they can be susceptible to network drop outs or patchy wifi.
As with above, these issues are network related with the only solution being refreshing the page or clicking out and back in to try and rectify the situation. Alternatively, you can wait for a stronger network connection, move to a different location or as a final resort, close/restart the app, browser or phone.
Where the recording has been taken on your phone, you can still access the file via the Prism library when you seek to upload the file again, so it isn't lost.