: Manuel PIQUET
4D have simplify the problem, now for 4D v17.1 the minimum os is now
10.12.6; but during a long time, the minimum os for the v17 was 10.11.x
If you go back in history, you will notice a pattern.
4D supports the latest 3 macOS versions.
Usually (but there is no guarantee), it is possible to build a macOS application running on 3 different Apple API sets. You can see this like a range, a window. It could be 10.10, 10.11 and 10.12. Or 10.12, 10.13 and 10.14.
Whenever we want to add support for a newer OS, an older one falls out of that range.
When 4D supported 10.13, 10.10 went away.
Now, with supporting 10.14, 10.11 went away.
Based on the behavior of the last years, we expect that supporting 10.15 will mean to stop supporting 10.12.
Note that Apple itself only supports the latest 3 versions. 10.12 is currently the oldest version getting security updates. If you are still using 10.11, the latest security updates provided was 6 months ago, meaning using this system is a high risk. At least customers located in Europe using computers to handle personal data (such as phone numbers or email addresses) will see conflicts with GDPR, so being forced to update to 10.12 (which could force to replace the hardware).