Very strange behaviour:
Regarding to the post from Lawmen (thank you!) I tried today his proposal - even Umberto was speaking from a coincidence - and copied the old .pye-file after reinstalling and re-registration of Hawaii-1 only (without GSX !!) into the mentioned couatl-folder. After running FSX I checked first PHNL and PHTO, everything o.k. and so I tried to go to PHLI - and was very happy to see all buildings - see first screenshot in the attachments! But ... but only for 10 sec, then they disappeared, but this time not the couatl-menu - see second screenshot. So, my pleasure was very short and I went back and took the "new" .pye-file again, but couatl-menu crashed in Lihue as before, so I de-activated the Lihue-scenery inside the FSX-scenery-library.
I did not give up and tried the old .pye-file again, but in the meantime the PHLI-scenery was deactivated in the scenery-library. Nevertheless, I checked what happens now in Lihue and I was very surprised - I realised all the FSDT-Lihue-buildings as well the palms around without any couatl-crash - although the Lihue-Scenery is de-activated !?!? - see third screenshot! But there are some constraints, e.g. that AES is not working - because the scenery is deactivated of course - and there are signs on the taxiways - see last screenshot.
So, for me it is a compromise-solution at the moment, but this behaivior is very strange.