Expression error but cannot be solved

[Anonymous]

I'm currently using the dataflow, and I want to refresh the dataflow. But I find that I cannot refresh because there is a problem in my source data. Since I've deleted a useless column in my source - sharepoint list, but it turned out that the dataflow cannot find this column. How to solve this issue?

[wdx223_Daniel]

try to check your M code in the Advance Editor, find the missing column names, and amend it or delete it