This can however happen even if you don’t have the document open in another application.
If so, close this application and try again. It could be because you have the document open for editing in another application. In some situations, this can however occur when the “other user” is you.
This is an expected behavior and before you can edit the document, the other user first needs to release it/check it in. You will also get the same error message if you try to: If you try to edit a document that either has been checked out to someone else, or if the document that you try to edit does not have support for coauthoring and someone else is editing it, you will get this error message: Applicable browsers: Any browser Description
