Autodesk 123D Design - movement is slow, "Application Not Responding" - quick fix

Hello,

This is a quick fix to those who use 123D Design on a Mac and have found that it responds very slowly. This happened to me on my newer iMac (2015 i5 - after Catalina, rolled back) and Mac mini (2012 i7 - always). This did not occur on my mid-2012 MBP.

Symptoms:

In 123D Design, grabbing the little cube in the upper-right corner to change the view's orientation will result in very slow movement. The 123D Design icon may show "Application Not Responding."

Resolution:

In 123D Design, click Edit Grid. I use millimeters. The default grid size was relatively large. I changed the Width and Height to 10mm x 10mm, but you can go smaller if you wish. Once I did that, movement was quick and the application was usable.

[Edited by Moderator]