Just tried EXACT same video (and project) but OPENING IN CUBASE 8.5.x (old vid engine) - works perfect. In 9.0.30 I only get video and NO wav file. 
Just tried EXACT same video (and project) but OPENING IN CUBASE 8.5.x (old vid engine) - works perfect. In 9.0.30 I only get video and NO wav file.