• Which the release of FS2020 we see an explosition of activity on the forun and of course we are very happy to see this. But having all questions about FS2020 in one forum becomes a bit messy. So therefore we would like to ask you all to use the following guidelines when posting your questions:

    • Tag FS2020 specific questions with the MSFS2020 tag.
    • Questions about making 3D assets can be posted in the 3D asset design forum. Either post them in the subforum of the modelling tool you use or in the general forum if they are general.
    • Questions about aircraft design can be posted in the Aircraft design forum
    • Questions about airport design can be posted in the FS2020 airport design forum. Once airport development tools have been updated for FS2020 you can post tool speciifc questions in the subforums of those tools as well of course.
    • Questions about terrain design can be posted in the FS2020 terrain design forum.
    • Questions about SimConnect can be posted in the SimConnect forum.

    Any other question that is not specific to an aspect of development or tool can be posted in the General chat forum.

    By following these guidelines we make sure that the forums remain easy to read for everybody and also that the right people can find your post to answer it.

FSX:SE Please Help Me fix this problem

As I already wrote, no problem here (why ever). I'm on FSXA only. However, I'm wondering whether the doubled ICAO might cause the error (an infinitesimal small difference might cause strange effects - or not. Chaos Theory... :duck:).
So your saying that the ICAO is what causes the game to crash? but I place it in the right region to be called "EG".
An ICAO code is unique and is used as such in the simulator as single identifier. For "playing" with ADE or other tools try to find fictional ones or do it based on stock airports. You can't do anything wrong. You only need to delete the compiled results and everything will be as before.
Axel makes a good point - never use a stock ICAO for a user added airport. To be clear if you want to modify a stock airport then load that into ADE and make the mods. ADE will handle the updating of the airport. If you want to 'invent' you own airport or add one that is not stock then do not use an ICAO that is already in the Sim but add one of your own. FS does not mind if you add your own, it does not like it if you use and existing one for something not related to the original airport.
Anything will work provided if is not the indent for a stock airport in the sim. You can check if it already exists by using ADE try opening a stock airport with that ICAO. ADE will tell you if the isn't is already used.
So your saying, "for an example that ICAO "EGLW" could change to say like ICLW". Would that work?
"EGL1" would do it too. As Jon already wrote there is a function in ADE telling you such doublet.
You could use as well Pete Dowson's MakeRunways tool (it's free) giving you back tables you could search for ICAO codes (or any string) or even Plan-G, as well a useful freeware. Both tools are building their data upon the used (active) airports in you sim.
As Axel suggested, when I create new ICAO codes I try to keep the first 2 or 3 letters the same, and change only the last letter(s).