August 2017 Update?

Hi all, I have updated PowerBI desktop last night. I have a script I'm reusing every month to read multiple excel files from a folder and apply some transformations on the data, sicne I have updated to the august version I keep on getting this error:

Expression.Error: The column 'Day' of the table wasn't found.
Details:
Day

Also when got back to read the script from the reports produced in a previous month I got the same error again! although it was working perfectly before the update!!!

I looked for solutions in the community but none applies to this!! 

Help please!!

Here's the full script:

let
ImportDaily =
let
Source = Folder.Files(<Folder Path>),
#"Removed Other Columns" = Table.SelectColumns(Source,{"Content"}),
#"Added Custom" = Table.AddColumn(#"Removed Other Columns", "GetExcelData", each Excel.Workbook([Content])),
#"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Content"}),
#"Expanded GetExcelData" = Table.ExpandTableColumn(#"Removed Columns", "GetExcelData", {"Name", "Data", "Item", "Kind", "Hidden"}, {"Name", "Data", "Item", "Kind", "Hidden"}),
#"Removed Columns1" = Table.RemoveColumns(#"Expanded GetExcelData",{"Hidden"}),
#"Added Custom1" = Table.AddColumn(#"Removed Columns1", "RemovedRows", each Table.Skip([Data],5)),
#"Added Custom2" = Table.AddColumn(#"Added Custom1", "PromotedHeaders", each Table.PromoteHeaders([RemovedRows])),
#"Added Custom3" = Table.AddColumn(#"Added Custom2", "DateFill", each Table.FillDown([PromotedHeaders],{"Day"})),
#"Added Custom4" = Table.AddColumn(#"Added Custom3", "RemoveChannel", each Table.RemoveColumns([DateFill],{"Channel"})),
#"Added Custom5" = Table.AddColumn(#"Added Custom4", "RemoveFileName", each Table.RemoveColumns([RemoveChannel],1)),
#"Removed Columns2" = Table.RemoveColumns(#"Added Custom5",{"RemoveFileName"}),
#"Added Custom6" = Table.AddColumn(#"Removed Columns2", "UnpivotData", each Table.UnpivotOtherColumns([RemoveChannel], {"Start GP", "Day"}, "Attribute", "Value")),
#"Removed Other Columns1" = Table.SelectColumns(#"Added Custom6",{"UnpivotData"}),
#"Expanded UnpivotData" = Table.ExpandTableColumn(#"Removed Other Columns1", "UnpivotData", {"Day", "Start GP", "Attribute", "Value"}, {"Day", "Start GP", "Attribute", "Value"})
in
#"Expanded UnpivotData",
#"Filtered Rows" = Table.SelectRows(ImportDaily, each ([Day] <> "Total")),
#"Changed Type" = Table.TransformColumnTypes(#"Filtered Rows",{{"Day", type date}, {"Start GP", type time}, {"Attribute", type text}, {"Value", type text}}),
#"Replaced Value" = Table.ReplaceValue(#"Changed Type","--","",Replacer.ReplaceText,{"Value"}),
#"Changed Type1" = Table.TransformColumnTypes(#"Replaced Value",{{"Value", type number}}),
#"Renamed Columns" = Table.RenameColumns(#"Changed Type1",{{"Start GP", "5min"}, {"Attribute", "Channel"}, {"Value", "000s"}}),
#"Reordered Columns" = Table.ReorderColumns(#"Renamed Columns",{"Day", "Channel", "5min", "000s"}),
#"Renamed Columns1" = Table.RenameColumns(#"Reordered Columns",{{"Day", "Date"}}),
#"Filtered Rows1" = Table.SelectRows(#"Renamed Columns1", each ([000s] <> null))
in
#"Filtered Rows1"

Thank you !