WSDL import with basic auth in SOAPUI 5.3.0

Hi there,

I'm trying to create a new SOAP project from a https WSDL with HTTP basic authentication using SoapUI 5.3. on a Windows(x64) based system. After hitting OK on the "New SOAP project" window, a new window titled "Basic Authentication" pops up but does not display any content and the application is stuck. Adding username and password into the URL is not an option in this case, as the password does contain a "@" and thus (at least to my knowledge) rules out using something along the lines of 

https://username:password@someURL

Any suggestions?

Thanks

Ulf