Plesk 12.x / Linux :: Installer Fails Because Sources Cannot Be Read From List

I am trying to update Plesk but whenever i try do so with the installer, the update fails because data is somehow added to /etc/apt/sources.list and sources cannot be read anymore. This happens both with the admin panel and the command lines.

Here is the command I'm running:

Code:
plesk installer --all-versions --select-product-id plesk --select-release-latest --show-components >/dev/null && plesk installer --version

Here is the output :

Code:
Doing restart of Parallels Installer...
File downloading products.inf3: 100% was finished.
File downloading plesk.inf3: 10%..20%..30%..40%..50%..60%..70%..80%..90%..100% was finished.
File downloading ppsmbe.inf3: 18%..79%..99%..100% was finished.

[Code] ....

And here is the content of my /etc/apt/sources.list file after the command is ran:

Code:

root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin

[Code] ....

The piece of data above the sources keeps coming back everytime I run the command even though I'm deleting it.