Reproduction steps:
1. Open the attached project;
2. Open the scene "SampleScene";
3. Build the game on WebGL;
4. Open the built game in the browser.

Actual result: the video does not show up.
Expected result: the video should show up in the screen.

Note: the video does not show up because it can not get video height and width. In the JS library the functions:
WebGLMovieTextureHeight: function(video)
{
return videoInstances[video].videoHeight;
},

WebGLMovieTextureWidth: function(video)
{
return videoInstances[video].videoWidth;
},
do not work.
Also, the sound of video is playing. The user modified the WebGL script: the script was committed to MeshRender, the user modified it to RawImage.

Reproduced with: 5.3.6p4, 5.4.2f2, 5.5.1p1, 5.6.0b5
Reproduced on Chrome and Firefox browsers.