Today I faced an issue with the deletion of a folder in a SharePoint 2010 document library. The folder was empty (viewed with admin account too), but could not be deleted.
Clicking the delete button resulted in the popup stating:
"The file is currently checked out or locked for editing by another user."
Tried deleting via all possible means (Explorer mode, Datasheet Mode, Power Shell), but with the same result.
Some blogs suggested deleting using SharePoint Designer 2010, but could not find a way to do so using SPD. Would be grateful if someone pointed out a link where it is explained how to view list/doc lib items using SPD and working upon them.
While researching the issue I browsed to:
"Document library settings --> Manage files which have no checked in version"
On the resulting page I found there was a file under the problematic folder and this file was checked out to a user. Look for the folder name under the Location column.
Took ownership of the document and published a major version, after which I was able to delete the folder :)