I had the same issue. The permissions on the "Applications" folder in my home directory were wrong. To be honest I'm not 100% sure of what the proper permissions and ownership should be, but I just added write permissions for me. There are lots of way to do this, but what I did was:
- Launch "Terminal"
- By default you should be in your Home folder, if not
cd ~
- Check permissions on the folder with the command
ls -l
The result was (result truncated to only show the first 2 lines
total 15216
drwxr-xr-x 3 root staff 96 Sep 27 2022 Applications
Note in this case I'm not root, but I am in the staff group. The permissions above mean:
d = directory
"rwx" = Owner permissions, Read, Write ,eXecute
"r-x" = Group permissions, Read, NO-write, eXecute
"r-x" = Others permissions, Read, NO-write, eXecute
Since I, as a member of the group but not the owner, didn't have write permissions the failure made sense. So to fix that I issues the command:
sudo chmod 775 Applications
This requires you to be an admin user, and you'll need to enter your password at this point.
Looking at things after:
ls -l
total 15216
drwxrwxr-x 3 root staff 96 Sep 27 2022 Applications
So now the group, has write permissions.
This allowed me to save the web app.