title: Expression.Error: We cannot convert the value null to type Text. Details: Value= Type=Type
body: <p>I want to combine multiple files with different headings and i found this <a href="https://www.youtube.com/watch?v=wKglApDFMog" rel="nofollow noreferrer">video</a> which was perfect. I get up to minute 12 and it fails and i get this error &quot;Expression.Error: We cannot convert the value null to type Text.
  Details:
  Value=
  Type=Type&quot;</p>
  <p>my code for the power query is <code>= Table.TransformColumnNames(stuff_Table, each List.Accumulate(Table.ToRecords(Headings), _ , (state, current)=&gt;Text.Replace(Text.Upper(state), current [BEFORE],current[AFTER]) ))</code></p>
  <p>I want to combine three files. One with a template that will be used for tableau but is otherwise blank, and the other two files with the data but in inconsistent formatting. How do i fix this?</p>