Hi Umberto!
I have the same problem. I found a workaround:
- You need to translate the simulator language into English.
My case:
URSS Airport from Digital Design. When loading, I get an error. My language in the simulator is RUSSIAN. I go to the simulator menu, change the simulator language to ENGLISH and you can immediately press the GSX button and it will work.
In the log in the attachment, up to line 618, the language was RUSSIAN.
and an error appeared: "emulateText_MSFS [GSX] 'utf-8' codec can't decode byte 0xd1 in position 31: unexpected end of data RED 6".
Then I switched to English and everything worked.
Problems only in this airport. In the same ULLI from Digital Design, or UUDD there are no problems.
There are also no gaps in other scenes from other authors.
UPD:
Forgot to add for reference:
I have Win 11, MSFS2024 Steam, GSX version 2.5.4 (complete reinstallation (according to your advice due to problems with pink textures)
The aircraft does not matter, PMDG or ini A350. The airport itself is important.
I did not change anything in audio devices and folders. This airport and GSX in it worked fine in version 3.4.7, then I updated ONLY GSX, lg 3.5.3, and the problem appeared. Today I deleted GSX via the installer and installed it from scratch, since there was a problem with pink catering textures.