Sony Movie Studio 12 Platinum build 1184

Have created multiple projects .... each includes a single MPEG video (1920x1080,25p) and one of more MP3 audio files on single audio track. The videos & MP3's play fine in isolation.
The individual projects range in duration from 10 - 25 mins.

I have only managed to render 2 so far .....
The render template is:
Main Concept Blu-ray 1920x1080-50i
Only change to it is to select '2 -pass' and set Max/avg/min rates to ... 25,20,15 Mbps

The failure happens at different times .. so not related to one particular frame, for example tried one project 3 times - 3 different failure points. My PC is pretty reasonable spec, certainly not a cheap laptop.
W7 64 bit - Quad core i5, 32GB RAM,2 TB HDD, has a good GPU ... but not option to use with this render template.
Nothing else running ... even turned off anti-virus and LAN card.

Tried one suggested fix of holding CTL+Shift & double click shortcut - to clear cache & rest defaults.

When it fails ... same each time get pop-up window stating “Movie Studio has stopped working” if I look at details same each time:
Problem Description
Application Name: Movie Studio Platinum
Application Version: Version 12.0 (Build 1184) 64-bit
Problem: Unmanaged Exception (0xc0000005)
Fault Module: C:\Windows\system32\OpenCL.dll
Fault Address: 0x0000000003411F31
Fault Offset: 0x0000000000001F31

Fault Process Details
Process Path: D:\Program Files\Sony\Movie Studio Platinum 12.0\MovieStudioPlatinum120.exe
Process Version: Version 12.0 (Build 1184) 64-bit
Process Description: Movie Studio Platinum