Exclusion is the way to go.
800 series only: Exclusion before inclusion applies to the 700 series and earlier chip sets. The 800 series devices will not exclude before they have been included; please factory reset the unit instead, then try inclusion again.
If you gave inclusion a try and were unsuccessful, try adding the ZSE18 Motion Sensor again and then trying the steps below once inclusion times out. VeraLite users - double check that your system is running on UI7 to ensure a smooth configuration process.
1. Tap the green Retry button in the bottom right corner of the app - this will put Vera into exclusion mode
2. Exclude the ZSE18 Motion Sensor by pressing and releasing the Z-Wave button THREE times quickly (the Z-Wave button is right next to the battery compartment)
3. Vera should confirm exclusion. The sensor will disappear from your device list
When dealing with older firmware, just press the exclusion ("-") button on Vera and try the exclusion process outlined above (though we highly recommend updating to UI7 to take advantage of all the security, compatibility, and interface upgrades that come with the new software).
After exclusion, give inclusion another try. And if that still doesn't solve the issue, don't hesitate to reach out!