Due to stronger security and privacy controls, you'll be prompted to grant Caffeine access to use Accessibility features to control your Mac.
If you're having trouble getting your Mac to stay awake on Mojave, please go to System Preferences > Security & Privacy > Accessibility and look for Caffeine in the list of applications. Ensure that the checkbox beside it is checked.
Should Caffeine not appear in the list, click the + button at the bottom and add it to the list, then check the box to grant permissions.
If you've granted permission, but Caffeine is not working as expected (e.g. your Mac still goes to sleep, even with Caffeine active), removing and re-adding Caffeine to the permission list typically helps.
While the permission system provided by macOS is robust and easy to use, it is also very complicated under the hood. In some cases, if you have more than one copy of Caffeine on your system (such as in your Downloads folder or in the Trash), macOS may internally reference that copy, rather than the one you are currently using.
This is especially true for users who have been using Caffeine for a long time, and may have previously used an older version of Caffeine on their Mojave or Catalina systems, as even after installing the latest version, in some cases macOS can become confused and internally is still looking for the older version.
Through extensive testing, much trial and error, and many reboots we have found that following the steps below should help to clear up these situations:
Be sure to remove any other versions that may exist, such as in your Downloads folder, and empty the Trash when finished. If you just installed Caffeine, also ensure that you have ejected the disk image by clicking the eject icon to the right of Caffeine in the Devices section of the Finder sidebar.
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