Microsoft’s office creates a temporary ownership file for their Excel and Word, this file is present in the location of the document, having “ ~$” followed by the name of the file. If the Excel file a Word file saved on the server then it is possible that the same file is getting used by another person at the same time. If you haven’t quit the Excel file properly then the Excel application becomes unable to delete the owner file and hence when the user tries to open/edit the Excel file then they get “The document is locked for editing by another user” error message.

There are lots of causes that can trigger this type of error and prevent the user from editing Excel or word file.