Cubase stops playing by itself

Happens very often since Cubase pro 8.5 - when first opening a song it’ll play for about 10 seconds - then stops by itself.

Only happens at first playback.

What the h* is going on???

Cubase Pro 8.5 (latest release) on El Cap

I get this quite a lot in Logic, with an out of memory error…

In Cubase quite often when I first play a project it will hit a new section where some new synths come in and kind of hiccup, sounds like a more extreme version of this?