Eddie,
All of the ZOOM development work (in more recent times) has been done on a Windows 7 desktop using the following versions of FTN95/Plato/salflibc.dll:
5.5.0.0 / 4.3.0.0 / 12.2.27.2
When running the developed executable on an XP machine, an older Salflibc.dll version is required (6.11.16.20). I don't know which operating systems the various users of ZOOM have, but none of them has ever complained of program failures.
A few weeks ago I downloaded the available PE FTN95 onto my Windows 8.1 desktop. The FTN95/Plato/Salflibc.dll versions are 7.1.0.0 / 4.6.4.0 / 16.4.27.11
Frankly, I don't like the new Plato as well as the old one. When the new Plato window is displayed after being minimized, it is corrupted beyond use, and I have to close it and reopen it.
The executable program that is created with the latest PE FTN95 on the Windows 8.1 machine has also failed on the Windows 8.1 machine, but, if memory serves, that same executable has run without error on the Windows 7 machine.
When all the failures to date (including a failure of the new PE Plato on the Windows 8.1 machine on one occasion) are taken into account, it appears (superficially at least) that there is some incompatibility between FTN95 and Windows 8.1 that is affecting ZOOM. Of course it is possible that there is something wrong with the ZOOM code, some insufficiency in the older version of FTN95 being used in development, or even something out of whack with my new Windows 8.1 desktop configuration that is causing the problem. But I don't really think so.
One reason that I gave the link for download of the latest ZOOM upgrade (not yet released) is to see if someone else on a different Windows 8.1 machine may not experience the 'stopped working' error. I should also note that one can be somewhat productive with ZOOM on a Windows 8.1 machine. He just has to be aware that the 'stopped working' error may occur. So far, the error has never occurred while the program is crunching numbers to determine the quasi-optimum trajectory.
I appreciate all of your comments and suggestions.