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 had the same issue, to resolve it, I preformed the following steps:
click on each row that is checked, one at a time and at the bottom right side of the window it will tell you if the resource is available or not. If that resource is not available then uncheck it. I then added the following resource site and this was able to fix the error. Name:Composite Marketplace Repository Location:http://marketplace.eclipse.org/repo
HOPE THIS HELPS...