Reproduction steps:
1. Open the attached project "VideoTest.zip";
2. Open "main.unity" scene;
3. Observe that there are two Quad components with Video Player attached;
4. Open Build settings, attach the "main" scene and build;
5. Open the build.

Expected results: both videos should play in the scene.
Actual results: The error occurs after launching the build:

Context: CreateObjectFromByteStream
Error details: The byte stream type of the given URL is unsupported.

Reproduced on: 2017.2.0b5, 2017.2.010, 2017.3.0a7.
Not reproduced on: 5.6.3p2, 2017.1.1f1, 2017.2.0b4.
Regression first occurred: 2017.2.0b5

Note: the video clip is .mp4 format and does not throw any errors in the Editor.