Pivot Column Error - There were too many elements in the enumeration to complete the operation.

adelmonte before you pivot the data, add an index column.

adelmonte try this script, start a new query, click advanced editor and paste this code, you can tweak it as you see fit and if works fine, apply it on your data.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WckksSVXSUTIyMDLUNQAhpVidaKWwxJzSVEOgOBLXCKQMzEXRY4ShxxhVjwmmHmMMPaaoesyUYmMB", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t, Column2 = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type text}, {"Column2", type text}}),
    #"Added Index" = Table.AddIndexColumn(#"Changed Type", "Index", 1, 1, Int64.Type),
    #"Added Custom" = Table.AddColumn(#"Added Index", "Group", each if [Column1]= "Date" then [Index] else null),
    #"Filled Down" = Table.FillDown(#"Added Custom",{"Group"}),
    #"Removed Columns" = Table.RemoveColumns(#"Filled Down",{"Index"}),
    #"Pivoted Column" = Table.Pivot(#"Removed Columns", List.Distinct(#"Removed Columns"[Column1]), "Column1", "Column2"),
    #"Removed Columns1" = Table.RemoveColumns(#"Pivoted Column",{"Group"})
in
    #"Removed Columns1"

My code 100% made sense. It you were unable to understand and that is a different story. 

it grouped the rows together. Anyhow your problem is solved that matters the most.