# FAQ

### **Why do I get an error saying "user already exist" when calling `cotter.signUpWithDevice` or `cotter.trustedDevice.enrollDevice` ?**

This function does 2 things: register a new user to Cotter and enroll the current device as a trusted device. Calling **`signUpWithDevice`** or `enrollDevice` for a user ID that already exist in Cotter will result in the error "user already exist".

For example, this can happen when you:

* Call cotter.trustedDevice.enrollDevice from an already trusted device.
* Call cotter.trustedDevice.enrollDevice from a device B, when device A has already been registered as a trusted device.

Also note that **`signUpWithDevice`**  & **`enrollDevice` only works on the user's first ever trusted device**. For additional trusted devices, you have to use the **Add New Trusted Device** method using the QR code.

### **What happens if you call `cotter.trustedDevice.getNewEvent` with a non-trusted device?**

Nothing happens. `getNewEvent` fetches a new un-approved authentication request that are generated when the user tries to login from a non-trusted device. However, since you're calling `getNewEvent` from a non-trusted device, this device cannot approve the request.

### **What happens if you call `signInWithDevice` or`cotter.trustedDevice.reqAuth` when you have not registered the user with Cotter yet?**

Will get errMsg: “Something went wrong”. You need a user that is registered to Cotter to be able to use any trusted device functionalities, except **`signUpWithDevice`**  & **`enrollDevice`** (because that function will also register a new user to Cotter for you).

### **What happens if you call `user.removeDevice` or`cotter.trustedDevice.removeDevice` from a non-trusted device?**

Will get err: “This device is not a trusted device.”


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