I'm very familiar with the problems of moving content between libraries. However, this is moving within the same library. I have inherited a site from a site owner who loved folders. I am working to add metadata and pull all the files out of the folders into just the library. This problem is NOT occurring with all files, but only with specific files (usually only one) in a folder.
I have two Windows Explorer windows open, one into the folder, the other into the library the folder resides in. In the Explorer window for the folder, I select the files to be moved. I drag them to the other explorer window, open to the library itself. 90% of the time, this works great. Occasionally, all but one of the files will move. That single file will throw the "cannot read source file or disk" error.
To further complicate things, if I attempt to access the folder using the Content and Structure feature, I get a SharePoint error.
I need to get these files out of the sub-folders. There are too many of them to download and re-upload. Suggestions?
Edited: I'm a site owner/administrator with no ability to use powershell or other back-end tools. SharePoint Designer is not allowed in our environment.