今天实盘交易中，出现如下错误提示。我是中午更新VNPY2.0.4到2.0.5。更新之前，早上运行一切正常，更新后触发成交后，就出错了。我检查是在self.put_event()时，事件处理程序中save_json()时出错的。
Traceback (most recent call last):
File "D:\vnstudio\lib\site-packages\vnpy\app\cta_strategy\ui\widget.py", line
246, in stop_strategy
self.cta_engine.stop_strategy(self.strategy_name)
File "D:\vnstudio\lib\site-packages\vnpy\app\cta_strategy\engine.py", line 688
, in stop_strategy
self.sync_strategy_data(strategy)
File "D:\vnstudio\lib\site-packages\vnpy\app\cta_strategy\engine.py", line 785
, in sync_strategy_data
save_json(self.data_filename, self.strategy_data)
File "D:\vnstudio\lib\site-packages\vnpy\trader\utility.py", line 105, in save
_json
ensure_ascii=False
File "D:\vnstudio\lib\json__init.py", line 179, in dump
for chunk in iterable:
File "D:\vnstudio\lib\json\encoder.py", line 431, in _iterencode
yield from _iterencode_dict(o, _current_indent_level)
File "D:\vnstudio\lib\json\encoder.py", line 405, in _iterencode_dict
yield from chunks
File "D:\vnstudio\lib\json\encoder.py", line 405, in _iterencode_dict
yield from chunks
File "D:\vnstudio\lib\json\encoder.py", line 438, in _iterencode
o = _default(o)
File "D:\vnstudio\lib\json\encoder.py", line 179, in default
raise TypeError(f'Object of type {o.class.name__} '
TypeError: Object of type int64 is not JSON serializable
为什么更新后就出现这个问题？请问应该如何解决？
