Chris Webb troubleshoots an issue:
One of the most common errors you’ll see when working with Power Query in Power BI or Excel is this:
Expression.Error: The key didn’t match any rows in the table
It can occur with almost any data source and in a wide variety of different circumstances, and for new users of Power Query it can be very confusing. In this post I’ll explain what the error message means and when you’re likely to encounter it using a simple example.
TL;DR You’re probably getting this error because your Power Query query is trying to connect to a table or worksheet or something in your data source that has been deleted or been renamed.
Read on to understand exactly what it means and how you can fix your code if you get this error.