数据少于100就会出现这个问题

如题，大家有没好办法怎样解决

回测下载数据出现错误：

File "e:\VNConda\lib\site-packages\vnpy\trader\database\database_sql.py", line 144, in save_all
DbBarData.insert_many(c).on_conflict_replace().execute()

File "e:\VNConda\lib\site-packages\peewee.py", line 1737, in inner
return method(self, database, *args, **kwargs)

File "e:\VNConda\lib\site-packages\peewee.py", line 1808, in execute
return self._execute(database)

File "e:\VNConda\lib\site-packages\peewee.py", line 2512, in _execute
return super(Insert, self)._execute(database)

File "e:\VNConda\lib\site-packages\peewee.py", line 2275, in _execute
cursor = database.execute(self)

File "e:\VNConda\lib\site-packages\peewee.py", line 2888, in execute
return self.execute_sql(sql, params, commit=commit)

File "e:\VNConda\lib\site-packages\peewee.py", line 2882, in execute_sql
self.commit()

File "e:\VNConda\lib\site-packages\peewee.py", line 2666, in exit
reraise(new_type, new_type(*exc_args), traceback)

File "e:\VNConda\lib\site-packages\peewee.py", line 179, in reraise
raise value.with_traceback(tb)

File "e:\VNConda\lib\site-packages\peewee.py", line 2875, in execute_sql
cursor.execute(sql, params or ())

IntegrityError: NOT NULL constraint failed: dbbardata.vt_symbol

发不了图片

v2.0.1从vnconda上升级v2.0.2启动问题，使用不了。如下图：

用2.0.1出现一些问题，vnconda安装
from vnpy.app.cta_strategy.backtesting import BacktestingEngine时提示ImportError: DLL load failed: 找不到指定的模块。

2.0版打开没有行情显示，怎样解决