I just bought Asset Forge and wanted to try it out by creating and exporting a very simple model.
Unfortunately I can't export this model as GLTF. I also can't open a new file after trying to export this model as GLTF until I restart the editor.
The problem doen't exist if I open a new file, add some random tiles and then try to export.
Here is the problematic model: https://pastebin.com/KYR7z4y1
The problem also vanishes, if I change the shader for "glass" from "shader:Unlit" to "shader:Standard;valueA:0.35;valueB:0.5;".
"Unlit" seems to be the default for windows though.
Best of luck in finding and squishing that bug!
PS: A minor bug I also noticed: If the GLTF export is successful, the file is not saved as *.gltf but *.glb. The extension seems to be correct for the created file, but the export dialog won't list previously exported files and overwrites any existing files with the same name without warning.