Something to do with 5.5 version. Noticed same with PRO version.
Disabled Proxy service and it works fine on both.
I went to Preferences - Proxy Settings - and selected "none". Is there another proxy service setting somewhere? B/c that did nothing
For me it was not about the setting on SoapUI. It was the network proxy my company had.
Ahhh yes I've had that issue with many apps, however this issue is not that. SOAP UI will not obtain an OAuth2 token on my work network or my home network. My work does SSL inspection and redirects, my home doesn't do anything like that.
In my case the exact same details worked on postman for our devs. So I knew the data was correct & it was easy to debug and pinpoint it as a proxy and SoapUI issue.
A tool like Fiddler will also cause this issue with SoapUI. If you see an error 'Page can not be loaded' and you are sure you have everything correct then its a network issue.
Good luck
