element-resize-detector: [Unable to reproduce] getComputedStyle().width not string in Embeeded Facebook WebView on Android

I have got a error report from this detector.

Cannot read property 'indexOf' of undefined

Stack Trace

ownerDocument.body || a.ownerDocument.body.contains(a)
}
return !b(a)
}
 
function k(a) {
  var b = o(a).container.childNodes[0];
  return -1 === getComputedStyle(b).width.indexOf("px")
}
 
function l() {
    var a = getComputedStyle(b),
      c = {};
    return c.position = a.position, c.width = b.offsetWidth, c.height = b.offsetHeight, c.top = a.top, c.ri

User Information:

Timestamp
24/03/2017 05:15:26
Time On Page
1.832 seconds
More from this Visitor
Visitor Time
24/03/2017 05:15:35
Browser (Raw)
Facebook 93.0.0
Operating System
Android 5.1
Source IP
111.243.58.165
Viewport
360 x 519