Append Query Stack Overflow

[Anonymous]

After appending queries I run into a stack overflow error, I have done it with a similar amount of data from a similar query and not received this issue, repeating all of the steps. 

Attached is the trace, I cannot find any ValidationException in the trace so I'm unsure as to what is the actual error is. 

The query looks like this 

let
    Source = AzureDataExplorer.Contents("yyyyyyyyyyyyyyyyyyyyy", "xxxxxxxxxx", "    let stime = datetime(2020-07-16 00:00:00);#(lf)    let etime = datetime(2020-07-16 23:00:00);#(lf)    Common2#(lf)    | where SiteId ==('yyyy')#(lf)    | where TS between (stime..etime)#(lf)    | where Tag == 'xxxxxxxxxx'#(lf)    |sort by TS asc#(lf)    |serialize TS#(lf)    |extend Value = tolong(Value)#(lf)    |extend newsession=iff(isnull(prev(Value)) or ((Value) <= 250 and prev(Value) > 250), 1, 0)#(lf)    |extend session_id = row_cumsum(newsession) ", [MaxRows=null, MaxSize=null, NoTruncate=null, AdditionalSetStatements=null]),
    #"Appended Query" = Table.Combine({Source, Query3}),
    #"Added Conditional Column" = Table.AddColumn(#"Appended Query", "Main Mixer Weight", each if [Tag] = "yyyyyyyyyyyyyyyyyyyyy" then [Value] else null),
    #"Changed Type1" = Table.TransformColumnTypes(#"Added Conditional Column",{{"Main Mixer Weight", type number}}),
    #"Changed Type" = Table.TransformColumnTypes(#"Changed Type1",{{"TS", type datetime}})
in
    #"Changed Type"

And the error happens during the following step: 

 #"Appended Query" = Table.Combine({Source, Query3}),

 I can upload the trace if this would prove useful.

Thanks

[v-chuncz-msft]

@Anonymous 

I cannot reproduce the issue. You may try Disable Power Query background refresh and create a support ticket for assistance if necessary.