In the main window click the newsgroups button (fig 3)

fig 3

The refresh newsgroups window will be displayed. You just have to wait.

In the beginning, the window should seems like this (fig 4) :

 

fig 4

 

then the list of newsgroups should appear in the window and the number of newsgroups should increase (fig 5) :

fig 5

The window will disappear at the end of the download.