Super hacky, thanks for testing and confirming. PlatformWebGL.GetBinaryFiles also has a check on UNITY_2021_2_OR_NEWER, it might be worth forcing that check to evaluate to true as well. If the issue really is that UNITY_2021_2_OR_NEWER is not defined then I imagine you would be getting issues with scene management and probably some deprecation warnings as well. Let me know if there are any FMOD related errors and I will investigate further