Updated to 2021 x64 SP0 but cannot see drawing in model or sheet space or cross hairs, just black.

Strangely, when I hover over the Draftsight icon in Windows toolbar, I can see the preview of the drawing.

Windows 10, i7 8Gig ram.

Updated my graphics card (Intel HD Graphix 4600) but no use.

Re-started computer.

Can anyone help please