Error when parsing from CTFd

[Mandalus]

Hello, I'm trying to use the UnityOpenApi parser with the CTFd Api, which can be found here: https://docs.ctfd.io/api/swagger.json
The parsing works well until it reaches the pages part, after which a "Nullable object must have a value." error is given, and the parsing is interrupted

Any idea on how to fix it?
I should mention that i'm using Unity 2019.3.5f1, and that i'm using the Parse from Asset method