Why is the sketch grid in my design workspace invisible?

Symptom:

Solution:

You may only have DirectX9 installed and not Direct3D 11. In that case, you will need to switch the renderer through the DSM options.

Make sure you have the latest DSM update: https://designspark.zendesk.com/hc/en-us/articles/360008126354-Is-there-an-update-to-DSM-available- 

Go to File -> DesignSpark options -> Advanced -> Graphics (Renderer). Drop down and choose DirectX9.