cannot use the accessibility ppa on ubuntu 16.10

[Amir]

Hi,

when i added the ppa on ubuntu 16.10 (i am using mate edition), and when 
i update (sudo apt-get update), it said errors when fetching the 
accessibility ppa, so i cannot get the latest version of orca and so on! 
can anyone help? errors are as follows:

"W: The repository 
'http://ppa.launchpad.net/accessibility-dev/ppa/ubuntu yakkety Release' 
does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore 
potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user 
configuration details.
E: Failed to fetch 
http://ppa.launchpad.net/accessibility-dev/ppa/ubuntu/dists/yakkety/main/binary-i386/Packages 
404  Not Found
E: Some index files failed to download. They have been ignored, or old 
ones used
  instead.
user at user:~$
"

hth!