If you have moved files from one hosting to new one, please kindly check if the wp-content/uploads/download-manager-files
directory and download manager files exist or not. If not available please copy the files from your old site wp-content/uploads/download-manager-files
to the new wp-content/uploads/download-manager-files
folder. I hope then it will resolve your issue. please kindly check and let me know.
Thank you and regards