Fingers crossed for you Craig.
I first suffered from this problem after installing 5.0.0.4, but with hindsight, it could all be coincidence. However, I recall eseeing exactly the same locked up (Infinity) screen that could not be cleared by Task Manager. Ultimately, I did a tedious complete restore of Windows 10 Pro and reinstalled all software. I guess this step must have cleared out the corrupt <settings> folder.
I then had another computing/power crash. BTW, am not blaming Atik! It was at a time when I was experimenting with different WiFi and Power options for my remote controlled EAA rig. I repeatedly updated my Atik core software (there have been many iterations) and Infinity/Horizon ran sluggish and often disconnected. However, Sequence Generator Pro ran fine.
Then, I noticed in the Change Log that 5.0.4.6 fixed a "Horizon disconnection" problem. So I downloaded that and then 5.0.4.7. By coincidence, I had another power glitch (local power cut due to high winds). Infinity locked up with the same screen that I first saw in April. I tried a complete reinstall, but stopped short of a Window restore. I had a chat with Andrew, he spoke with the software guys. This issue was fixed simply by deleting the <settings file> under ProgramData > Atik > Infinity > and allowing the software to restore it. No need to fully restore Windows. My Infinity/Horizon is now running in true "real time" and all my long woes seemingly gone.
If Vince or Andrew are picking up this thread, it might be an idea to try to find a way to ensure that any corrupt local <settings> data is cleaned out on any software update or reinstall. In my experience, Windows does seem to want to hang onto it (like it has done in the past with redundant drivers). Good luck Craig, but I think this might also work in Dusk. ...