¿por qué mi nube función de seguir dando un error (CloudFirestore con ForOf Bucle)?

Mi función getDocuments() en resumen consiste en que me pase algunos parámetros en una matriz (como la ruta, el nombre del documento, si quiero sección por partes) y se basa en que la matriz puedo devolver el contenido de cada documento a través de un bucle (ForOf), la función que yo lo hago más que nada para salvarme demasiadas líneas de código, el problema es que siempre me lanza un error de que no sé lo que es.

Me pueden ayudar? Por favor

La nube de la función

export const employees = functions.https.onRequest((request, response) => {
corsHandler(request, response, async () => {
    return await security.securityLayer(
        { _definedMethod: "GET", userValue: request.method },
        { _definedType: true, _definedLevel: [4], _definedSeconds: 12, userToken: request.header("_token") },
        { required: false },
        { required: false }
    ).then(async (answer) => {
        if (answer.status === 400 || answer.status === 401) {
            return response.status(answer.status).send(answer);
        }

        return await security.getDocuments([
            { collection: "Core/", documentName: "Centers", options: { idReturn: "centros", nestedProperties: [] } },
            {
                collection: "Core/", documentName: "Employees", options: {
                    idReturn: "personal",
                    nestedProperties: [
                          { idReturn: "employees", name: "employee" },
                          { idReturn: "submanager", name: "submanager" },
                          { idReturn: "manager", name: "manager" }
                     ],
                },
            },
        ], SPECIAL_CODE).then((documents) => response.status(documents.status).send(documents))
            .catch(() => response.status(500).send(security.error500(SPECIAL_CODE, 2)));
    }).catch(() => response.status(500).send(security.error500("SPECIAL_CODE", 1)));
});
});

async función

export async function getDocuments(
documents: {
    collection: string,
    documentName: string,
    options: {
        idReturn: string,
        nestedProperties: {
            idReturn: string,
            name: string
        }[]
    }
}[],
code: string):
Promise<{ status: 201, code: string, subcode: number, devDescription: string, data: any }> {
const data: any = {};
const response: { devDescription: string, subcode: number } = { devDescription: "The document was found and retrieved successfully.", subcode: 1 };

if (documents.length > 1) {
    response.devDescription = "Documents were found and obtained successfully.";
    response.subcode = 2;
}

for (const iterator of documents) {
    const docRef = { path: iterator.collection, name: iterator.documentName };
    const options = { id: iterator.options.idReturn, nestedProperties: iterator.options.nestedProperties };
    const doc = await database.collection(docRef.path).doc(docRef.name).get();

    if (!doc.exists) {
        data[options.id] = "The document " + docRef.name + " does not exist in the specified path: " + docRef.path;

        if (documents.length === 1) {
            response.devDescription = "The document was not found. Check the DATA for more information.";
            response.subcode = 3;
        } else {
            response.devDescription = "One, several or all documents were not found. Check the DATA for more information.";
            response.subcode = 3;
        }
    } else {
        const docData: any = doc.data();
        if (options.nestedProperties.length === 0) {
            data[options.id] = docData;
        } else {
            for (const nested of options.nestedProperties) {
                data[options.id][nested.idReturn] = _.get(docData, nested.name);
            }
        }
    }
}

return { status: 201, code: code, subcode: response.subcode, devDescription: response.devDescription, data: data };
}