I have experienced this issue and it is usually solved by one of these steps:
- Disable firewall and anti-virus (Better option is to configure access rules and allow your app through firewall or real-time antivirus protection)
- Restart Mendix Studio Pro and run app again
- Verify that port 8080 and 8083 is not being used by some other application
- Uninstall make it native app and install again