请问这是怎么回事？
打开白屏

点击开始回测后就是这样

无法加载策略，点击开始回测触发异常
Traceback (most recent call last):
File "d:\vnstudio\lib\site-packages\vnpy_ctabacktester\ui\widget.py", line 350, in start_backtesting
old_setting = self.settings[class_name]
KeyError: ''

在做CTA回测时交易策略无法加载
输入本地代码点击开始回测出现以下代码
Traceback (most recent call last):
File "d:\vnstudio\lib\site-packages\vnpy_ctabacktester\ui\widget.py", line 350, in start_backtesting
old_setting = self.settings[class_name]
KeyError: ''