After installing the PyDev plugin for Eclipse (by feeding http://pydev.org/updates in Eclipse's Install new Software window) I'm getting the following errors when launching Eclipse:

What is it? What should I do?
I'm using Eclipse 4.2.0.
After installing the PyDev plugin for Eclipse (by feeding http://pydev.org/updates in Eclipse's Install new Software window) I'm getting the following errors when launching Eclipse:

What is it? What should I do?
I'm using Eclipse 4.2.0.
You're probably better using Eclipse Marketplace, from the website or through Eclipse itself, instead of providing the direct link.
This happens because you have a link to the Aptana Studio update site in your updates and you're marking to check all update sites.
As PyDev has optional dependencies on Aptana Studio, it'll gather those plugins, but getting Aptana Studio that way (partially) doesn't work properly. So, uncheck the option to get updates considering all update sites during the install process or remove the aptana studio update site.