black screen when changing scene in WebGL using Unity 5.6

We switch scene in our game which works perfect on Windows, Mac and Android. In WebGL, our start menu scene unloads and then we are stuck. The display turns black, there are no errors, warnings no debug logs. When we test this with two empty scenes in a new project there is no problem. When we add two empty scenes to our project to switch just between those two it fails. What can be in our project that makes the scene switch fail? We have this problem since our switch from Unity 5.5 to 5.6.1f1.

We already launched a version made with Unity 5.5 but we can't deploy all our updates and bugfixes because we made them in Unity 5.6. Please help us find the cause of this error as we don't have any information (logs or whatever) that support us in finding the bug.

 

When creating the build for Android we used the option "Split Application Binary" at the Player settings. Of course this setting is stored in the project. It just happens to be the setting that makes scene switching in WebGL impossible! After some hard work in stripping down our project it occurs that this is the only setting that causes the bug. I really don't know why an Android setting ends up having a major impact on a WebGL build. Something Unity should investigate!
(using Unity 5.6.1f1)

 

Thank you, @roland_k! I was starting to despair about building a WebGL version of our game Luxuria Superbia. Thank you for sharing this!