I always get the same error on my local machine and on a hosted sever - a few other have reported it also ( and others have it working successfully) but so far nobody has got to the bottom of how to get around it - even tried setting write permissions in the directory but so far no go
The reason I ask is that this did not work for me. I have my website on one machine and my sql server on another .
What I found was that the backup was trying to write to the file located on the sql server. That file did not exist.
When I created the folders on the sql machine the backup worked. It wrote to the folder on the sql machine.
Still not able to get the import products working. Another issue.