哪位老铁遇到过这个问题，帮帮忙，谢谢啦!
报错如下：
: 触发异常已停止
Traceback (most recent call last):
File "C:\vnstudio\lib\site-packages\vnpy\app\cta_strategy\engine.py", line 588, in call_strategy_func
func()
File "C:\vnstudio\lib\site-packages\vnpy\app\cta_strategy\strategies\dual_thrust_strategy.py", line 53, in on_init
self.load_bar(10)
File "C:\vnstudio\lib\site-packages\vnpy\app\cta_strategy\template.py", line 239, in load_bar
use_database
File "C:\vnstudio\lib\site-packages\vnpy\app\cta_strategy\engine.py", line 521, in load_bar
symbol, exchange = extract_vt_symbol(vt_symbol)
File "C:\vnstudio\lib\site-packages\vnpy\trader\utility.py", line 27, in extract_vt_symbol
symbol, exchange_str = vt_symbol.split(".")
ValueError: not enough values to unpack (expected 2, got 1)
