When installing a Fusion 360 app from the Autodesk App Store, the installer simply copies the so called bundle (hence the .bundle extension on the folder) into the appropriate "ApplicationPlugins" folder - the location depends on where you installed Fusion 360 from:
- Fusion 360 installed from the Autodesk web site: ~/Library/Application Support/Autodesk/ApplicationPlugins
- Fusion 360 installed from the Mac App Store: ~/Library/Containers/com.autodesk.mas.fusion360/Data/Library/Application Support/Autodesk/ApplicationPlugins
For some reason, you may have the access rights for the folder set to "Read only", and so the installer cannot write into it:
And that can cause the installation to fail:
You can simply right-click on the correct "ApplicationPlugins" folder, select "Get Info" and provide "Read & Write" in the "Privilege" column for your account.
Hopefully, that should solve the issue.