当在hmmlearn包中使用model.score时，为什么会出现“'diag'混合Covar必须为非负数”错误？

我已经进行了一个月的继续语音识别工作，并且找到了hmmlearn包裹。我可以使用_model = hmm.GMMHMM(...)和创建我的音素模型_model.fit(...)。但是，当我想将_model.score（_extracted_test_features）用于测试样本时，出现了以下错误：

.format（self.covariance_type））ValueError：'diag'混合Covar必须为非负数

这是我的代码：

    def Main():
        # ---
        _phoneme_files_dir = './database_info/phonemes/phoneme_files/'
        _phoneme_dataset_dir = './database_info/phonemes/extracted_features/'
        _phoneme_models_dir = './database_info/phonemes/models/'
        _phoneme_test = '/home/ali/speech_recognition/database/database_english/timit/data/lisa/data/timit/raw/TIMIT/TEST/DR1/FAKS0/SA1.wav'
        # ---
        _phoneme_test_features = ExtractFeatures(_phoneme_test, 9640, 11240)
        _phoneme_models, _phoneme_models_list_loaded = LoadModels(_phoneme_models_dir)
        print("Getting models has successfully done")
        # ---
        _score_list = {}
        for _model_label in _phoneme_models.keys():
            _model = _phoneme_models[_model_label][0]
            _score = _model.score(_phoneme_test_features)
            _score_list[_model_label] = _score
        _predict = max(_score_list, key=_score_list.get)
        print("predict result phoneme is ", _phoneme_models_list_loaded[_predict])

有人知道这个错误吗？我找到了一些解决方案，但是几年前，在hmmlearn软件包得到一些更新并修复了它们之后。