WebView in SharedProject works on iOS not on Android

I tried to play a video from a web-url in a WebView. It works fine on iOS but not on Android. When i debug it on Android the WebView is loaded but i see only a black screen instead of the expected video.
The stack reports --
"[chromium] [ERROR:gl_surface_egl.cc(153)] No suitable EGL configs found."
"[chromium] [ERROR:gl_surface_egl.cc(620)] GLSurfaceEGL::InitializeOneOff failed."

What is wrong, could anybody help?

The video would also be played fine in a standalone Android-Project.

Thanks for help