This is my advice.
I have tried to check my installation of Megascenery and there is nothing that can be trouble our scenery in this way So.
My opinion is that something is corrupted inside Megascenery and create this trouble.
Do a check disk before doing anything.
Select your SSD, then tools tab click Check Now, it will tell that windows is in use, cancel and then click on schedule disk check.
Once you restart windows it will check your SSD, after booting deactivate your Antivirus (always) .
I advice to re download Megascenery with the tool you used to download PHNL, in the mean time uninstall as normal with your tool or via windows official uninstall , and be sure to delete the folder of megascenery if still there.
No need to unistall FSDT Airport
Install Megascenery with administrator right(very important) right click "Run as Administrator" then apply the patch same as administrator method.
In FSX Library manager move Megascenery down below all Hawaiian airport.
An advice for the next time don't install FSX and add-on in Program Files (x86).