Update Error! v3.821

Describe the bug

I don't know if these things are related, but Fusion360 isn't recognizing the third mouse button. So I thought I'd look for an update. However when I go to update I get this message:

"Update Error!

BetterTouchTool can’t be updated when it’s running from a read-only volume like a disk image or an optical drive. Move BetterTouchTool to Applications folder using Finder, relaunch it from there, and try again.

Cancel Update"

It's definitely in the applications folder and not on a CD or VD.

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):

trying to get the middle (MagicMouse v1) button functionality back in Fusion360

Pretty sure Fusion was recognizing the middle button the other day. But Fusion did just have an update so it could be on that end also.. Not sure where to go from here.

Screenshots
Update Error!

Device information:

  • Type of Mac: 4,1 (Early 2009) upgraded to 5,1 running Catalina via DosDude patcher.
  • macOS version: 10.15.7 (19H2)
  • BetterTouchTool version: v3.821

Update - BTT does work in Fusion360 as expected at work on my NNMP, but forgot to get details, though I'm pretty sure everything is pretty much up-to-date.

Update 2 - I clicked "Reset all settings" and almost instantly got a popup asking to move BTT to the Applications folder. So I did and it moved from wherever it thought it was I guess. BTT is now updated, but didn't fix fusion not recognizing middle click.