Hi @james_west ----- Thank you for the report and my apologies for the troubles here.
I have seen a few reports (example #1 and example #2) of this behavior, which ended up being the result of a Win10 update (KB4013429) not interacting with the Intel HD 4000 graphics driver properly. As you can see, we are not the only ones being affected by this, other similar reports here, here, and here.
Thus far, the two work arounds I have heard from other users is to either A) Reinstall the graphics drivers OR B) Try running the 32 bit version of Roon.
Let me know what you think about giving either of the above a shot.
-Eric