Recent files that I need are being taken offline automatically on my Mac.

Hey @ColbyN, let's see what we can find about this together! 

When did this behavior start happening on your end? 

Also, does this happen with files you initially create using the website (and they later sync locally to the device) or with content that you create locally within the Dropbox folder? 

One more thing I'd like to know is if your hard drive is running out of available space, by any chance. 

Keep me posted, and we'll take it from there!

Thanks for the help. It's been happening for at least a few weeks, but I believe longer. I didn't start  remembering specific files that un-downloaded themselves until the current project I'm working on. When I go to Dropbox's "manage hard drive space" window, I can see that there are files downloaded to my computer that have been untouched for several years, which I imagine should've been automatically removed if that's a feature that can't be turned off.

These are files I created on my computer, not through Dropbox in a browser.

My hard drive has had over 100GB of free space this whole time.

I haven't done any macOS updates for a while.

Hey @ColbyN, thanks for the info! 

That sounds a lot like what this Help Center describes. 

If the files that became automatically online-only didn't have a sync icon initially (meaning that their status was "available"), then I understand that this is expected.

Have you tried selecting the files in question, and right clicking on them in order to change their status to "available offline"? And if so, do you still notice the same behavior after doing so? 

If this isn't the case, please reach back out with a screenshot showing the sync icons on your files before they become online-only.

I think I'm starting to understand. These files were opened by a third-party application, so there is no green check mark. Does this mean that files and folders with no icon next to them (downloaded but not manually set to "make available offline" can be automatically removed from the computer, even if there is well over 100GB of free space, and even though there are other files that have been untouched for years that are still downloaded? And this is outside of any iCloud Drive settings, and can't be turned off?

Hey @ColbyN, indeed, you'll need to keep making those files available offline manually.

Have you tried freeing up some hard drive space, by making online-only files you no longer use, to see if that has any effect on the particular files that you constantly need to access?

Thank you. I do occasionally free up hard drive space that way. I noticed recently that in Dropbox's Manage Hard Drive Space window, it says that a lot of files are downloaded (I can check the box and click on Move to Online-only) but if I visit that folder, they're not actually downloaded.

But I'll make sure I manually keep certain files online during projects instead of letting other software download the files, since they can then be un-downloaded any time.