The Dropbox badge will let you know that others are editing the file by turning red and displaying a lock icon. You’ll still be able to edit, but the badge is there to warn you that if you and the other person continue editing at the same time, you may create different versions of the file.
Exclamation mark: You and a collaborator are both editing the file
When you and another person are editing a file at the same time, you’ll see the Dropbox badge turn red with an exclamation mark icon. When you see this, you have the option to save your version of the file, and we’ll help the other person get your latest changes. If the other person saves their changes to the file before you save your changes, you’ll see the badge turn blue with a download arrow and you can update to their version.
Note: When working in an Excel file, the badge may always display an exclamation mark (even if you or other viewers have not yet edited a spreadsheet). We suggest that you ignore the exclamation mark. When your collaborators make and save any actual changes, follow the steps to update to the latest version of the document. Choose to discard your own changes or save them in a separate version through the badge.
Download arrow: You can update to your collaborator's version
If you and someone else are both in the same file and the other person saves their changes, the badge will turn into a download arrow, indicating that you don’t have the latest version of the file. You can update to the latest version from the badge.