Hi @wu cong?
Sorry for the late reply, with the screenshot you've shared looks like there is some issue with the connection in Datasource which has been used, perhaps you could please check if the datasource is still valid by clicking on it on the 'flow view' page. Also, maybe opening the transformer too would throw a similar exception.
Once errors are resolved, then you should try to run the job
I hope this helps, feel free to share details if required
Thanks
Rohit Bhaskar