Meaning of "site1xxx" (FTP file/folder owner)

The owner "site1xxx" (e.g., site1152, site1163, site1184) appears when the FTP user account that created the folders/files in question has been removed from the list of FTP user accounts.

To regain access to these files for modification, you need to log in with a different FTP account in the FTP Manager file manager and change the owner of the files using the "Properties" button.