Hi Phill.
Sorry, It's been a lot of months since this problem, but yet, I face the same one.
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Graphic design tool:
[GPU Information]
GPU Device: NVIDIA GeForce GTX 970
GPU RAM: 4096 MB
GPU Driver API: DirectX 9.0
GPU Driver Version: 1.7.633
GPU Driver Date: 12/12/2016
[Graphics Effects Settings]
Anti Aliasing: Off
Ambient Occlusion: On
Object Shadow: On
Ground Shadow: On
Ground Reflection: Off
Selection Display Style: Normal
Transparency Effect: Better Performance
[Limit effects to optimize performance]
Off
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Also: I've seen that you can actually zoom in a lot in the center of the model, but where the canvas "dissapear" there is some sort of limit. After that "limit" the canvas will dissapear.
I did have Chrome open, but that doesn't seem to be the problem