[Expression.Error] The column '<column title>' of the table wasn't found. When the column is there.

[LeeBecker]

Hello,

I often get the error [Expression.Error] The column '<column title>' of the table wasn't found.

I know that this means that the query can't find a particular column, but I often get the error even when the column does exist. I'm confident that it is not an error in my query because when I refresh the query a minute later without changing anything, it runs fine.

I don't mind TOOOO much from my point of view because I know that it will work when I refresh it, but the problem is, I have created queries for other people, and every time they get the error, they ask me why it is happening, or they think my query doesn't work. Also, sometimes they have changed the data, so the error really is valid.

Is this a bug is Power Query? Could it be a connection problem? Is this a known problem? Does anyone else get this problem? Does anyone have any suggestions for how to fix it?

Thank you!!!

Here is my code:

let

    Source = Excel.Workbook(Web.Contents("https://**********/LiveWebinar registrant_list.xlsx"), null, true),
    #"Expanded Data" = Table.ExpandTableColumn(Source, "Data", {"Column1", "Column2", "Column3", "Column4", "Column5", "Column6"}, {"Data.Column1", "Data.Column2", "Data.Column3", "Data.Column4", "Data.Column5", "Data.Column6"}),
    #"Lowercased Text" = Table.TransformColumns(#"Expanded Data",{{"Data.Column3", Text.Lower, type text}}),
    #"Removed Duplicates" = Table.Distinct(#"Lowercased Text", {"Data.Column3"}),
    #"Removed Top Rows" = Table.Skip(#"Removed Duplicates",1),
    #"Promoted Headers" = Table.PromoteHeaders(#"Removed Top Rows", [PromoteAllScalars=true]),
    #"Renamed Columns" = Table.RenameColumns(#"Promoted Headers",{{" First name", "First name"}, {" Surname", "Surname"}, {" email address", "Email address"}, {" Are you:", "Are you:"}}),
    #"Removed Other Columns" = Table.SelectColumns(#"Renamed Columns",{"First name", "Surname", "Email address", "Are you:"}),
    #"Trimmed Text" = Table.TransformColumns(Table.TransformColumnTypes(#"Removed Other Columns", {{"Are you:", Text.Trim, type text}, {"Email address", Text.Trim, type text}, {"Surname", Text.Trim, type text}, {"First name", Text.Trim, type text}})
in
    #"Trimmed Text"