box-api - +[NSJSONSerialization ensureObjectForKey:inDictionary:hasExpectedType:nullAllowed:] でのアサーションの失敗

Question

私は box-ios-sdk-v2 (v1.1.0) を使用しています。

[[BoxCocoaSDK sharedSDK].foldersManager folderInfoWithID:BoxAPIFolderIDRoot
                                          requestBuilder:nil
                                                 success:folderSuccess
                                                 failure:failure];

アサーション エラーが発生します。

*** Assertion failure in +[NSJSONSerialization ensureObjectForKey:inDictionary:hasExpectedType:nullAllowed:], ~/MyApp/Pods/box-ios-sdk-v2/BoxSDK/Categories/NSJSONSerialization+BoxAdditions.m:27
An uncaught exception was raised
+[NSJSONSerialization(BoxAdditions) ensureObjectForKey:inDictionary:hasExpectedType:nullAllowed:]: Unexpected JSON null when extracting key modified_at from dictionary {
    "content_created_at" = "<null>";
    "content_modified_at" = "<null>";
    "created_at" = "<null>";
    "created_by" =     {
        id = "";
        login = "";
        name = "";
        type = user;
    };
    description = "";
    etag = "<null>";
    "folder_upload_email" = "<null>";
    id = 0;
    "item_collection" =     {
        entries =         (
                        {
                etag = 0;
                id = 1092326452;
                name = CSS;
                "sequence_id" = 0;
                type = folder;
            },
                        {
                etag = 1;
                id = 680411078;
                name = New;
                "sequence_id" = 1;
                type = folder;
            },
                        {
                etag = 2;
                id = 8224096128;
                name = ".apdisk";
                "sequence_id" = 2;
                sha1 = e8389b6e4307a798b0811cabc94144ce381b3312;
                type = file;
            }
        );
        limit = 100;
        offset = 0;
        order =         (
                        {
                by = type;
                direction = ASC;
            },
                        {
                by = name;
                direction = ASC;
            }
        );
        "total_count" = 3;
    };
    "item_status" = active;
    "modified_at" = "<null>";
    "modified_by" =     {
        id = 181198661;
        login = "grigutis@iu.edu";
        name = "John Grigutis";
        type = user;
    };
    name = "All Files";
    "owned_by" =     {
        id = 181198661;
        login = "grigutis@iu.edu";
        name = "John Grigutis";
        type = user;
    };
    parent = "<null>";
    "path_collection" =     {
        entries =         (
        );
        "total_count" = 0;
    };
    "purged_at" = "<null>";
    "sequence_id" = "<null>";
    "shared_link" = "<null>";
    size = 289;
    "trashed_at" = "<null>";
    type = folder;
}

これは私のアカウントの問題ですか (modified_at は実際には null であってはなりません)、それとも SDK の問題ですか? それが私のアカウントである場合、どうすれば修正できますか?