Problems adding dependency to project

Hi, I am unable to add a Maven library as a dependency to a Java/Gradle project. I get as far as selecting the library from the drop down list on the Download Library From Maoven Repository. But whenclick OK, I get the following popup message indicating that no files were downloaded:

I

I have IDEA configured for a manual proxy server, which works just fine (e.g., I can download plugins).I am running IDEA 14 CE under Mac OS X 10.10.3.

I am at a loss as what to do. Any suggestions would be greatly appreciated.

Roger Alexander.