Vuforia failed to initialize...

So this seems to be a common error with more than one cause
http://stackoverflow.com/questions/37950316/vuforia-failed-to-initialize-on-android-l
https://developer.vuforia.com/forum/qcar-api/failed-initialize-vuforia

My application runs fine in the editor
But after deploying to device my application launches but with the Vuforia popup error.
Am targeting Android on a Samsung TAB S2.
Latest unity Pro 5.5.1, OpenGLES2.0.

Can anyone suggest next troubleshooting steps?
It...

Vuforia failed to initialize...