This is a short post today and a change from the Synology focus posts since this site began, I recently rebuilt a Mac from a bare hard drive. As part of the process I had to restore an OmniFocus archive file.
The OmniFocus archive is what stores all the old completed or dropped projects and completed tasks. This is a regular OmniFocus data file that can be opened manually.
The OmniFocus Archive is always called Archive.ofocus-archive although its location will vary depending upon the version and where you purchased OmniFocus.
To get the location you can look at this OmniFocus support document. The file isn’t in the Backup directory listed in the article but it is one level up. So for my sandboxed version 2 purchased directly from OmniFocus the archive file is in:
I simply had to grab that file from a backup, put it back, and then the next archive simply added to this file.