"enable editing" issue occurring in Power Query

[ursua]

Hi,
So i have two different excel files with queries in them running on csv files downloaded from a tool.
One of it is working as usual, it refreshes and everything is ok, while the second one throws an error "[Expression.Error] The key didn't match any rows in a table."
The workaround that resolves this issue is to open csv files, enable editing and then save.
The question I have is why one of the query works normally, does not require to enable editing while the second one needs to have those data files with "enable editing" option.
As long as I have this workaround it is not a problem for me, I am just curious if this is a question of some kind of settings or what.
First query (couple of first rows):

Source = Folder.Files("C:\folder\folder\folder"),
    #"Filtered Rows3" = Table.SelectRows(#"Source", each Text.Contains([Name], "file")),
    #"Removed Columns2" = Table.RemoveColumns(#"Filtered Rows3",{"Name", "Extension", "Date accessed", "Date modified", "Date created", "Attributes", "Folder Path"}),
    #"Invoke Custom Function1" = Table.AddColumn(#"Removed Columns2", "Transform File from file", each #"Transform File from file"([Content])),
    #"Removed Other Columns1" = Table.SelectColumns(#"Invoke Custom Function1", {"Transform File from file"}),
    #"Expanded Table Column1" = Table.ExpandTableColumn(#"Removed Other Columns1", "Transform File from file", Table.ColumnNames(#"Transform File from file"(#"Sample File (3)"))),
    #"Changed Type" = Table.TransformColumnTypes(#"Expanded Table Column1",{{

Second:

Source = Folder.Files("C:\folder\folder\folder"),
    #"Filtered Rows" = Table.SelectRows(#"Source", each Text.Contains([Name], "file")),
    #"Removed Columns2" = Table.RemoveColumns(#"Filtered Rows",{"Name", "Extension", "Date accessed", "Date modified", "Date created", "Attributes", "Folder Path"}),
    #"Filtered Hidden Files1" = Table.SelectRows(#"Removed Columns2", each [Attributes]?[Hidden]? <> true),
    #"Invoke Custom Function1" = Table.AddColumn(#"Filtered Hidden Files1", "Transform File from file", each #"Transform File from file"([Content])),
    #"Removed Other Columns1" = Table.SelectColumns(#"Invoke Custom Function1", {"Transform File from file"}),
    #"Expanded Table Column1" = Table.ExpandTableColumn(#"Removed Other Columns1", "Transform File from file", Table.ColumnNames(#"Transform File from file"(#"Sample File"))),
    #"Changed Type1" = Table.TransformColumnTypes(#"Expanded Table Column1",{{"

Any idea?