Reproduction steps:
1. Open attached project.
2. Go to "Edit > Project Settings > Player > Other settings".
3. Make sure "Virtual Reality Supported" checkbox is disabled.
4. Build and run the project.
5. Notice that Splash Screen is shown.
6. Repeat step 2.
7. Enable "Virtual Reality Supported".
8. Go to "Edit > Project Settings > Player > Splash Image".
9. Notice that "Show Unity Splash Screen" is enabled.
10. Build and run the project.

Actual result:

• For a very short time a white window is shown instead of the Splash Screen.

Expected result:

• Splash screen is shown.

OR

• A warning about incompatibility between VR and Splash Screen is shown in the Editor.

Reproduced with: 5.4.0b3, 5.4.0b18
Not reproducible with: 5.3.5f1, 5.4.0b2
Reproducible with no VR software and hardware.