How to de-register a targeted in a daqri app, after it was found so I can reuse it.

Good day,

I am working on a Daqri application. What the app does it searches for a marker and activate tasks and when the user presses finish it should return to scanning. And search for the same marker and repeat the same tasks.

But when I re-scan at the moment it says "The target 'C:/Users/Dondoo Studios/Desktop/Daqri Unity Project/Assets/StreamingAssets/3ybml_small.png' is already registered.
UnityEngine.Debug:LogWarning(Object)". Meaning I can't re-scan the same marker.

Please help