Only immediately after loading and pressing play for the first time in a session
Be aware of this setting:
By default this should be off. It can be On because then it allows faster launching of WaveLab, if you don’t need playback.
But when it is Off, the audio card is initialized late. Maybe, if you press Play during that time, some problem occurs.
IOW, wait a few seconds after WaveLab is open, to start playback.