Device not allowed (remove other GPS receiver)

Derro

RaceChrono v4.0.9, Qstarz Q818XT, Sony Z3 compact (Android 4.4.4):

The phone and Qstarz pair. In "Settings" for Device 2 I am able to select 3rd option (bluetooth receiver) but receive message "Device not allowed (please remove other GPS receiver)"
The only other GPS receiver is the phone's, but it is not activated before turning on RaceChrono and doesn't appear to be turned on during the process (ie not selected when asked if I want to turn on internal GPS and the GPS icon is not shown on phone).

The phone's GPS is OK for distance and location but has an error of about 20% on speed when used with other sport (eg cycling) apps. What is the work-around for this problem.(Apologies If it has already been addressed in the Forum, but couldn't find it.)
Derro

aol_of_RaceChrono

This is an usability issue in the app and needs fixing at some point. Go to all of the devices in RaceChrono settings, and one by one uncheck the "enabled" checkbox. After that you should be able to configure the new GPS. Problem is you have another GPS device enabled in RC settings (possibly device #1), as RC allows only one to be enabled at a time.

Derro

Looking good! Won't know for sure until I get to the track, though the "new track" option might enable me to check functionality on the street eg a few times around the block (at legal speeds).
Derro

aol_of_RaceChrono

You can do test runs without having a track. Just start recording and drive around. You can see the route details in analysis screen when you tap the "Route" button. Naturally laps won't appear, but the data is still viewable!