Expression.Error: We cannot convert a value of type List to type Text.

Hello,

Thank you for your detailed explaination. I tried what you told me and used the generic function. Unfortunately it didn't work. Here is the code of the query I hava so far. Can I add a line within this query, that transforms the list within the cells into text?Probably before the changed type line, since after that line, there is not written List within the cells of the columns "hashtag" and "category" anymore, but Error. I would prefer not to open up a new query.

let
 Source = SharePoint.Tables("https://hilti.sharepoint.com/sites/de001101", [ApiVersion = 15]),
 #"3860ef3e-aef8-4ee7-bc63-1c29b67a7e9f" = Source{[Id="3860ef3e-aef8-4ee7-bc63-1c29b67a7e9f"]}[Items],
 #"Changed Type" = Table.TransformColumnTypes(Custom1,{{"Idea Title", type text}, {"Date of Idea Entry", type date}, {"Submitter", type text}, {"Hashtag", type text}, {"Mealsize", type text}, {"Idea Status", type text}, {"Ranking of Idea", type text}, {"Meal Size", type text}, {"Implementierung", type text}, {"Category", type text}, {"Hashtag", type text}}),
 #"Removed Blank Rows" = Table.SelectRows(#"Changed Type", each not List.IsEmpty(List.RemoveMatchingItems(Record.FieldValues(_), {"", null})))
in
 #"Removed Blank Rows"

Also, I will create two new queries afterwards, to reorganize the columns "hashtag" and "category". One example for hashtag:

let
    Source = IdeaList,
    #"Select Columns" = Table.SelectColumns(Source,{"Idea Title", "Hashtag"}),
    #"Split Column by Delimiter" = Table.ExpandListColumn(Table.TransformColumns(#"Select Columns", {{"Hashtag", Splitter.SplitTextByDelimiter(",", QuoteStyle.Csv), let itemType = (type nullable text) meta [Serialized.Text = true] in type {itemType}}}), "Hashtag"),
    #"Trimmed Text" = Table.TransformColumns(#"Split Column by Delimiter",{{"Hashtag", Text.Trim, type text}})
in
    #"Trimmed Text"

I did not write that code...