If you are getting Failed to zip files. pclZip error (-10): .Unable to find End of Central Dir Record signature error, please check the following.
Check if your WP server has enough disk space
Check if the write permission to the wp-content/infinitewp/backups folder is 666 or 777 (writable by PHP)
Check if there is enough memory to backup, large sites. You can try excluding some directories using exclude option while backing up
