I did not find anything on google about this error.
Error Deleting File: Portal Root\\ DNN file manager error...file names
The process cannot access the file \'Portal Root\\ Courseware in French\\ file name.zip\' because it is being used by another process.
This error occures when uploading files or just moving them from one folder to another using the admin file manager.
The files still move successfully after the error.