Help, I need an interpretation of an rsync error (11) {"error in socket I/O"}

My backup script was working fine, I commented them out to test another entry in my backup rsync and when I uncommented them I had this error:

== begin
rsync error: error in file IO (code 11) at main.c(784) [Receiver=3.2.3]
== end

my backup script is as follows:

== begin
rsync --verbose --archive --delete --progress --stats /root home/BACKUP_1/
rsync --verbose --archive --delete --progress --stats /home/kevin home/BACKUP_1/
rsync --verbose --archive --delete --progress --stats /home/PUBLIC home/BACKUP_1/
rsync --verbose --archive --delete --progress --stats /home/VDO home/BACKUP_1/
rsync --verbose --archive --delete --progress --stats /home/VIDEO home/BACKUP_2/
== end

Now, when I enter the command line manually, it works fine, the file/script permissions are 700, so it IS executable for root.

So what happened, and does anyone have any suggestions on how to fix it?

Thank you for your time, and have yourself a beer and a good day!