This might happen if another VPN service is already enabled on the Android device. Please try the following steps:
- From your apps list > select Settings.
- Select Connections.
- Scroll down to More Connection Settings.
- Select VPN.
- Tap on the blue settings cog next to the VPN name.
- Select Delete VPN profile.
Then try clicking on the 'Retry' button and it should work fine. If the issue still persists, send an email to our Email Support with more details like your device make/mode, OS version running on it and we will investigate further.