This is because the file path name where the file is located is too long.
The files required will need to be moved to a folder higher up the folder path temporarily or given a shorter name to be uploaded.
The character length of the path name is 250 characters.
Online Enquiries Error 'Path name too long...' when using the get files function
When uploading files to the Online Enquiries module an error is received stating the file path is too long and the files will not upload.
Written by Andrei Ene