Per the 4D v11 SQL Language reference, error code 1409 is an error during backup that generally occurs from a read error for files to be backed up or a write error during file backup.

Here are 3 possible causes of this error, and the steps for how to resolve them.

1. Disk permissions:
   In order to perform the backup, you must have read permissions on all the files that are going to be backed up, and read-write permissions on the folder that the backup will be written to.


2. Not enough disk space:
   Make sure there is enough space to perform the backup.


3. Error with the Backup.xml Preferences file:
   Simply delete the Backup.xml file and then re-set the backup preferences.