Unable to export frame

Hi,

      I'm unable to export frame using the export frame button(Ctrl+Shift+E) when I click this button nothing happens, though it works in the Premiere Pro 15.4V(standard) version but doesn't work in the beta version. 

After I Button Editor to reset layout, but still nothing happens. Export frame is not working. Please do check on this issue, it happens in the Beta version only, I'm using Windows 10 and system/graphics is compatible for beta version. Thank you!