Ensure you have a stable internet connection. Try to switch from Wi-Fi to mobile data, and vice-versa.
If there is no problem with your internet, follow these simple steps:
1. From the PIN screen, click on the "Need Help" button at the right top corner.
2. Click on the "Logout" button on the pop-up message box.
This should fix the PIN page problem. However, if the issue persists, update your app to its latest version on Play Store/App Store. If your app is already updated, please uninstall and reinstall the app.
Disclaimer: Do not share your PIN or OTP with anyone. CoinSwitch will never ask you for your PIN or OTP.