On Lucas Chess 11.15b (note: it would be useful were the version information available from the program mid-game - call that problem '0'), (1) to set up a position and play it seemingly one needs to do: tools -> create your own game -> arrange position -> (wonder what to do, and) -> Utilities -> Play game -> choose colour.
(2) When one starts playing, the animation speed seems to have changed from what it normally is (at least if one has changed the default - and one presumes, though falsely, global animation speed). This is jarring.
Please note finally that (3) trying to adjust the starting position, after one has started playing, if unintuitive and fiddly. One problem (3a) is a path box which one expects to be able to type into, but which, upon being clicked, opens a finder window. Another problem (3b) is that to save changes one needs to make them and then manage to locate a rather small, somewhat hidden little save icon.
Finally (4) somehow I ended up with three windows each showing their own board. At this point I was boggled and closed the program (by finding and closing all the windows).
All in all: a lot of 'papercuts' here. Indeed 4 is more than a papercut.