Uncaught TypeError: Cannot read property 'width' of undefined

Uncaught TypeError: Cannot read property 'width' of undefined
    at Object.WebcamService.webcam.onSuccess (WebcamService.js:56)
    at fn (eval at compile (angular.js:15351), <anonymous>:4:214)
    at Scope.destination.<computed> [as onStreaming] (angular.js:10546)
    at HTMLVideoElement.<anonymous> (webcam.min.js:1)

Any ideas?

Thanks 👍 