If you are getting this error when you try to install Time Doctor, the first step is to attempt to manually create a folder inside your ~/Library/Application Support folder. If you are not allowed to do so, then there probably is an issue with your permissions.
The complete path for the cache should be: ~/Library/Application Support/TimeDoctor.
To solve this, you'll need to "right click" on your /Applications folder, select "Get Info" from the menu and follow the instructions here:
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