The first time I open the data viewer, and try to select a subfolder for the data, I get a 'Network Connection Error'. Closing the tab/window and opening it again causes it to work properly. This has occured for several datasets, but most recently for UWO170N on godel
I was able to reproduce the problem. It is related to CAS and redirection between services (ie between /ss and /ssdata).
The fix has been pushed into the 'anise/unstable' branch in the repository.