"Are you sure you want to delete this file" error message

• Delete shared files or folders from your Dropbox folder on your computer.
• Move files or folders from a shared folder to a location that other members of the folder can't access (like a private folder or a folder not in your Dropbox account).
• Move files or folders out of your Dropbox folder.

If you didn’t mean to delete or move these files, click Cancel. If you want to confirm the delete or move, click Delete or Move respectively. 

If you’re deleting files to save space on your hard drive, try using selective sync or setting your files to online-only instead. 

Requirements to undo accidental deletions on macOS

The Dropbox specific filesystem warnings are only available on Mac devices running macOS 10.15 or newer with Full Disk Access enabled to undo accidental deletions.

If you need to enable Full Disk Access you can use the following steps:

1. Open System Preferences and click Security and Privacy.
2. Click the Privacy tab.
3. In the bottom-left, click the lock icon to make changes.
4. Enter in your computer password and click Unlock.
5. Scroll down to Full Disk Access and check the box next to Dropbox.
6. Click Quit Now to quit and restart Dropbox app.