After running recommend / analyze patches,

I've run the recommend / analyze patches for 2 patches, and it's completed (although with a warning in the last step) - I've looked at the log, but that says "Warning: Metalink credentials are not set.  Download of patches skipped".  The rest seems to have worked okay, so I don't think that is anything to worry about.

To then look at the impact, I click on the "Details" option under recommended patches results, and the recommended patches results page is displayed.

however, when I click on the impact button it's not doing anything. 

There's also a "Select" check box on the left hand side which I can't click on to put a tick in (nor does select all work), so I can't view the aggreate patch impact.