Found the problem, finally.
In the most current Hawaii1 .PYE file, we added a new dynamic type of Windsock (that reacts to the wind), which was introduced in Hawaii2 but, unfortunately, it's missing from the Hawaii1 installer which means, the only users affected are those using the very latest version of Hawaii1 but don't have Hawaii2 installed.
Reverting to the previous .PYE file which didn't called the new Windsock "fixed" the problem, but of course you were left without any Windsock...
Here's attached the Windsock from Hawaii2, to be put into the FSX\Simobjects\Misc folder, together with the other FSDT* objects.
You don't need this if you have Hawaii2 installed and, of course, we'll update the Hawaii1 installer now, to include it. It's just strange that Couatl crashed without logging the error in the Couatl.ERR file, this is something we'll check too.