I\'ve been up for hours now, searching online for a solution. I can happily say, this has really pissed me off.
Upon opening \'Install New Software\' I get \"\'Contactin
I have encountered the same problem. I have resolved disabling the site using:
Window → Preferences → Install/Update → Available software Site
Here the site that can be used have a tick (enabled). You must find the site that caused the problems and disabled them.
I hope this could be useful.