[HELP] 2019 Crashing at outline creation

Hi all,
My Kubla 2019 keeps crashing when trying to apply creation of a Manual (but auto calculated) outline of Design Contours.
The design contour has ~4000
It has an Existing surface uploaded via DXF. 
This is the point before it closes. Once I click OK, the program just disappears.
Note it also crashes if I manually draw a smaller area (jsut around the lower basin).
Any ideas?