In the Device Setup, could you please check that the correct driver is loaded?
Next thing to try, go to Play Mode and choose Play > Apply Default Playback Template.
If that doesn’t do, could you start a new simple project and try what that does for you?
For the HALion window, go to Play Mode. On the right side you see the list of instruments. To the left of “HALion Sonic SE” there is a button with a strangely shaped ‘e’. Click on that (maybe twice) and the HALion window shall come to front.