One of my student mentioned me on Twitter that Precise Repository (Ubuntu 12.04) is missing from UKDW Repository. I checked my configuration and i just realized that i accidentally edit the wrong release version. I was supposed to remove Oneiric since i have completed Quantal synching, but i deleted Precise.
Since i have a policy of supporting N and N-1 release, i had to resync all of the Precise repository from scratch. So far, i have completed backports, proposed, security, and updates branch. What's left is the main precise branch which is the biggest one. I think i still have to wait for 2-3 days to complete this process if there's no obstacle in the middle of the process.