This question already has an answer here:

I am facing a problem with /etc/apt/sources.list

The 52nd line appears to be malformed

Line 52: deb http://archive.canonical.com/ precisepartner

Line 53: deb-src http://archive.canonical.com/ precisepartner

This problem has caused Synaptic Package Manager and Ubuntu Software Center to not function properly and close abruptly.

marked as duplicate by Zanna, wjandrea, pomsky, Eric Carvalho, David Foerster Mar 19 '18 at 15:58

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • Please don't edit such system files if you don't know what you're doing. If you need to add repositories use either the GUI or add files in the /etc/apt/sources.list.d/ directory by adding a new file. – gertvdijk Oct 6 '13 at 13:48

Line 52 and 53 should be:

deb http://archive.canonical.com/ubuntu precise partner
deb-src http://archive.canonical.com/ubuntu precise partner

Note the missing ubuntu subpath and the missing space between precise and partner. (line numbers as for your situation, not in general)

Not the answer you're looking for? Browse other questions tagged or ask your own question.