Noticed a few errors

Normally I see an error and move onto the next plugin, But I found this one so useful that I would like to report the issues.

Notice: Undefined offset: 35 in wp-content/plugins/mk-simple-backups/class.backuphandler.php on line 121
Notice: Undefined variable: errors in wp-content/plugins/mk-simple-backups/class.backuphandler.php on line 218
Notice: Undefined variable: bkp_filename in wp-content/plugins/mk-simple-backups/mk-simple-backups.php on line 172
Notice: Undefined index: error in wp-content/plugins/mk-simple-backups/mk-simple-backups.php on line 206

https://www.ads-software.com/plugins/mk-simple-backups/