Apple recently released new versions of their operating systems, iOS and OS X (now called macOS).
iOS 10 was released over a week ago. At this time, there are no known problems with our iPad apps running in iOS 10 (this is unlike iOS 9, which caused a nightmare, and like all previous iOS releases, which did not cause problems). All of our iPad apps including Pretty Good Solitaire run fine on iOS 10.
MacOS Sierra (10.12) was released this week. At this time there are no known problems in any of our Mac apps except for Pretty Good MahJongg. Pretty Good Solitaire and all our other Mac apps except Pretty Good MahJongg appear to be running fine is Sierra. Again, most Mac OS updates have not caused problems, but some have.
The exception is Pretty Good MahJongg, which is crashing in Sierra. We are working to find out what the problem is and issue an update. In the meantime, if Pretty Good MahJongg for the Mac is an application that you use, we recommend not updating to Sierra until we can fix the problem.
As a side note, not once in over 20 years of updates has any update to Windows ever caused a crash in one of our games. Microsoft takes backwards compatibility with software very seriously. Apple simply doesn't care at all, in fact they regularly and gleefully cause old apps to stop working. This makes it much harder for Apple developers.