If the app won't connect, a clean install is often the fastest fix—delete the app and redownload it to reset the API configuration.
You must tap Allow when iOS asks to add VPN configurations; this is required to encrypt your traffic. IPVanish iOS API.svb
If you are seeing "API errors" or using a custom script, consider these troubleshooting steps from IPVanish Support : If the app won't connect, a clean install