To reproduce:
1. Open the attached project;
2. Load "DrinkMe" scene.

Expected result: editor doesn't crash when loading "DrinkMe" scene.
Actual result: editor crashes in AudioMixer::CheckConsistency ().

Note:
void AudioMixer::CheckConsistency ()
{
//If we are loading an old project with no start snapshot, then set it here to the first in the list
if (!m_StartSnapshot.IsValid ())
{
m_StartSnapshot = m_Snapshots[0]; <--- This causes the crash, there are no snapshots.
SetDirty ();
}
}

Reproducible on versions: 5.4.4p1, 5.5.0p4, 5.6.0b4, 5.6.0b6.