Premiere 2017 crashing - Ultra key?

Premiere Pro v2017 (11.0.1.6) has been crashing a lot when using the Ultra key filter. Also, it’s been dropping frames a lot. See the partial sequence image below, where I have had to render sections to make it playback smoothly.

First the Nvidia graphics driver complains, quits, and re-starts itself;

Unable to recover from a kernel exception. The application must close. Error code: 3
(subcode 2) (pid=4104 tid=1160 adobe premiere pro.exe 64bit)

Followed by premiere saying it must close. (crash report below).

The media is XAVC-S 1080p50 in a matching sequence. I have tried various drivers from Nvidia,

1. 376.33-quadro-grid-desktop-notebook-win8-win7-64bit-international-whql.exe
2. 375.86-quadro-grid-desktop-notebook-win8-win7-64bit-international-whql.exe
3. 368.39-quadro-grid-desktop-notebook-win8-win7-64bit-international-whql.exe  <<< Current driver

In that “reverse version order” but no change.

So, I rebuilt the project in Premiere 2015.2 and no crashes. (And did not need to render the bits I previously needed to.)

HP Z400 single 6 core CPU

Windows 7

24 GB Ram

Separate OS and Media drives

Nvidia Quadro 4000 graphics card.