Right click on screen and click on Inspect, this will open the browser's inspect window. 

  • If the message there is Refused to set unsafe header "user-agent" the uploading activity is still on and you can wait for it to be completed.
  • If the message there is net::ERR_TIMED_OUT or net::ERR_INTERNET_DISCONNECTED your internet connection is unstable. Please, contact the IT team to solve this issue.