Render Freezes 8.5 - AppHangB1

This is around the 5th time this has happened now.
Win7 64x

a) Select midi track of instrument to render
b) Render settings: Doesn’t seem to matter, randomly happens.
c) render
d) Freezes: Cntrl Alt Delete to close cubase

error:
Problem Event Name: AppHangB1
Application Name: Cubase8.5.exe
Application Version: 8.5.0.69
Application Timestamp: 562a8a9a
Hang Signature: 93e8
Hang Type: 2049
OS Version: 6.1.7601.2.1.0.768.3
Locale ID: 2057
Additional Hang Signature 1: 93e858bf125554c65fb2e4e37b58a321
Additional Hang Signature 2: c94b
Additional Hang Signature 3: c94b4bafb6df5dbeee1be126e1d00ab7
Additional Hang Signature 4: b28f
Additional Hang Signature 5: b28ffa6e12e246ba274ef5be0c5b29a0
Additional Hang Signature 6: c57a
Additional Hang Signature 7: c57a57c2eb9286db0c83dda4ba6bc555