Reikan does not make it easy to keep up with their software updates. I got the same message when I checked through my version 1.6 for updates. I had to go to the site and search for the new one. As I said in both of my NANPA articles about version 1.8.1, it does have bugs in it. I had it fail to do AF fine tuning three times on the first image capture. I found that switching from the new RAW analysis mode to JPEG fixed the problem. FoCal kept running out of memory with the BIG NEF files.
The good news is that it takes far fewer clicks now to determine the AF set point than it did with earlier versions.