Your log shows the problem:
- You used a custom GSX profile you either made yourself or downloaded from somewhere, which was made for P3D V4, which used a custom texture for the jetway logo, named KE
- P3D V5 doesn't support custom textures, it can only use jetway logos that are already included with it.
However, something is strange, because we thought about this, and there's specific code in GSX that, when it runs in P3D V5 and it finds an airport with a custom GSX profile using a custom texture made for P3D V4, it will IGNORE that logo, and will switch to default selection for that gate, and that is precisely to prevent the error you are seeing.
Also, if you try to edit the gates with the scenery customization page, a new copy of the GSX .INI profile will be made, containing a "p3d5only" setting, so you won't lose your original profile ( in case you use both P3D V4 and V5 ), so V4 will continue to use the old profile with custom textures and V5 will use the new one, preventing the errors.
I don't know why this doesn't work for you, because it should. Please attach your GSX .INI as well, perhaps there's another problem with it that is preventing from this system to work. File is named, per your log, as:
%APPDATA%\Virtuali/GSX\rksi-yv5jav.ini