Restore fails when trying to recover a file from remote storage

Installation 1. Configure FTP remote storage as described here https://docs.moodle.org/dev/File_System_API#FTP_file_system  or use the following commands. Apply the patch from attachment to create FTP filesystem class: git am --whitespace=nowarn < file_system_ftp.patch Add the following to your config.php : $CFG->alternative_file_system_class = 'core_file_system_ftp' ; $CFG->file_system_ftp_user = 'test' ; $CFG->file_system_ftp_pass = 'test' ; $CFG->file_system_ftp_host = 'localhost' ; $CFG->file_system_ftp_path = 'home/test/testing' ;  2. Install FTP locally (the following commands are for ubuntu): useradd -m test passwd test apt-get update apt-get install vsftpd ufw ftp ufw allow 20 /tcp ufw allow 21 /tcp 3. Set write_enable to YES in /etc/vsftpd.conf. 4. Restart vsftpd : service vsftpd restart 5. From the directory that has the file in it connect to FTP:  root @ec8b0e0ad064 :/siteroot# cd your-dir-with-file root @ec8b0e0ad064 :/siteroot# ftp localhost Connected to localhost. 220 (vsFTPd 3.0 . 3 ) Name (localhost:root): test 331 Please specify the password. Password: 230 Login successful. Remote system type is UNIX. Using binary mode to transfer files. Be sure that binary mode is set. 6. Create root directory for the storage: ftp> mkdir /home/test/testing ftp> mkdir /home/test/testing/filedir ftp> cd /home/test/testing/filedir 7. Upload the file from attachment ( b21d09a7fd8a3e5292060b5db4f4f5a412393c24 ): ftp> put b21d09a7fd8a3e5292060b5db4f4f5a412393c24 Test the patch Access Site administration > Courses > Restore course. Upload the backup from the attachment ( backup-moodle2-course-5-mock_course-20210204-0456-nf.mbz ). Go through the restore pages and perform restore. Confirm , the course is restored. Access the course and open Some file resource. Confirm , the file content is displayed correctly.