sir,
i've installed net speed moniter using oolka from google
but i've no longer needed it ... so i removed it ..

but after that i run cmd in my panel

i saw an error 404 not found i tried everything but still i can't solve it please help me

# sudo apt-get update
Hit:1 http://downloads.metasploit.com/data...-framework/apt lucid InRelease
Hit:3 http://dl.google.com/linux/chrome/deb stable InRelease
Ign:5 https://ookla.bintray.com/debian kali-rolling InRelease
Err:7 https://ookla.bintray.com/debian kali-rolling Release
404 Not Found [IP: 35.161.162.245 443]
Hit:2 http://ftp.harukasan.org/kali kali-last-snapshot InRelease
Hit:4 http://ftp.harukasan.org/kali kali-experimental InRelease
Hit:6 http://ftp.harukasan.org/kali kali-rolling InRelease
Reading package lists... Done
E: The repository 'https://ookla.bintray.com/debian kali-rolling Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

i am waiting for your reply thank you sir ,,,