Error message when using a one-time password (OTP) when logging into the CoinZoom app saying "Number must not be null."
To resolve this issue:
- Log into trade.coinzoom.com from a web browser (not in the app).
- If a QR code comes up in the browser, use that to link your authenticator on the phone to the customer's account.
- Log in to CoinZoom on your cell phone.