The problem only happens when trying to delete a vector file that I have manually added with the drawing tools (Line, Polyline, Rectangle…).
So I open a Sentinel-1 image, display one of the bands, and draw a new geometry (which is added to the Vector Data folder in the Product Explorer window). Then I select the geometry in the Product Explorer and try to delete it (mouse right click or Edit->Delete) but SNAP stops responding.
Deleting vector files that I have imported with File->Import->Vector Data works fine.
SNAP 2.0 beta 05, Windows 7