Unable to install Nu-Get from repository on Xamarin 4.2.2 on OSX 10.9.1
I'm running Xamarin Studio 4.2.2 on OSX 10.9.1.
I'm attempting to follow the installation instructions in the README:
https://github.com/mrward/monodevelop-nuget-addin/blob/master/README.md
I've opened up the Xamarin Add-In Manager, gone to the Gallery tab, and added the following repository:
http://mrward.github.com/monodevelop-nuget-addin-repository/4.0/main.mrep
However, when I then select mrward.github.com from the Repository list, it shows me:

If I go back and select All Repositories, and expand IDE extensions, I don't see Nu-Get listed.

Any thoughts?
Not sure. It seems OK for me. You could try adding the url again or just download the .mpack directly and then use the Install from File button instead.
I had the same issue, had to install from file as suggested