menu: File → Open … and then navigate to it, or double click in Finder the database package that you found.
What was the specific location that you found the database package? Hopefully not in a folder synced with a cloud service. I keep all my database packages in ~/Documents/DEVONthink/ folder. And hopefully with the upgrade macOS disk optimisation remains turned off.
Also, note version 3 is now in maintenance and will be retired at some point in the future. Version 4 is the active focus of development and we suggest moving to it sooner rather than later, if hardware permits it (and your machine does as you’re on macOS Tahoe).
Thanks everyone. Another rudimentary question. Why would I not want it in a folder synced with a cloud service? Isn’t everyone’s whole mac desktop synched with icloud at this point?
Why would you? If space is an issue, an external hard drive is cheaper and more secure. If you want a remote backup, a true backup service is comparably priced and more secure.
Cloud services are very useful for working on material across multiple devices. They are not nearly robust enough to “fire and forget” by sharing everything with them.