I solved the problem!!!

I deleted QCARWrapper.bundle and when re-importing, it works.

Same Error.

Wait for help.

not work for me

If you don't provide more details, it is imposibble to give you a solution:

When I had this problem, I made some tests and checks:

1.Check if Webcam is connected properly.

2. Check if you are using Unity 5 32 bits on Windows and Unity 5 64 bits on Mac.

3. Check if License Key is valid for VUFORIA Unity Extension 4.2.3 in case you have installed this version of the Vuforia pack.

Hope it helps. Regards.

1. My computer is a laptop, and the webcam is connected. I can use it to record videos. the device name is Lenove EasyCamera
2. System is a Win10 64 bit and the unity is 5.11f personel version.
3. I do not know the 3 very clearly, but my vuforia package is vuforia-unity-5-0-5.unitypackage

Thank you for your reply.

Hope the reply again.