Thanks, Mouser! I had the same problem, and it was easy to find the solution and apply a fix. I've been using FARR since 2010, and it's worked flawlessly the whole time.
I can only speculate, but I suspect installing the notorious Windows 10 1903 update is what messed things up. Using 1809, perfect, but after the final 1903 installation reboot, the config.ini message appeared when FARR started up.