You addressed your post to me but it was @slbaumgartner who gave you those steps.
You would need to look on your computer. Normally when you download the dmg for an application it ends up in your Downloads folder but you’ll have to look. Reinstalling SketchUp won’t affect your existing SketchUp models.
Mac sometimes ask you if you want to delete the installer at the end of installation.
It probably wouldn’t be smart to respond in the affirmative.
That’s programmed into some installers, but not done for SketchUp dmg. You have to manually eject the dmg after doing the install and then choose whether you want to move it to trash or keep it.
If you have lost the dmg, it may be difficult to get it again for 2021 as Trimble no longer supports that version.
Thanks for the updates…I have searched in my finder for dmg’s and in the download folder and unfortunately I can’t see a sketchup dmg which I presume means I foolishly deleted it…
If it’s not there, you can assume it’s been deleted. SketchUp 2021 is not supported and no longer available from SketchUp but there may be some other source. It wouldn’t hurt to get current with SketchUp, though.
You can still get SketchUp 2021 from this link.