SoapUI Repository not scrapeable

I added the SoapUI repository to Nexus, but I always get the message that the repository cannot be scraped.

I used the following URL: http://www.soapui.org/repository/maven2/com/smartbear/

The message appears using repository policy "Release", but also with "Snapshot".

Is there a way to integrate this repository into Nexus, or what am I doing wrong?

Thanks for your help!