The following code produces 4 different assertions upon compilation (the first 4 times, then the next 3).
It's probably not as minimal as it could be.
Angelscript 2.37.0 WIP via Openplanet 1.26.16
Images of the assertion errors can be found here: https://github.com/openplanet-nl/issues/issues/442

class Cache {
    Cache() {
    }

    protected Obj@[]@[] _Blah;
    const Obj@[]@[] get_Blah() {
        return _Blah;
    }

    protected void AddObj(Obj@ o) {
        while (o.pos.x >= _Blah.Length) {
            _Blah.InsertLast({});
            break;
        }
        _Blah[o.pos.x].InsertLast(o);
    }
}


class Obj {
    nat3 pos;
    Obj(nat3 pos) {
        this.pos = pos;
    }
}

If I replace Obj@[]@[] with Obj@[][] the exceptions don't happen.

Thanks!