Expression.Error: There weren't enough elements in the enumeration to complete the operation.

Hi - I am using a Grouped Rows function to produce two columns: Total Fees and Total AUM. Total AUM works, but Total Fees does not. 

I keep getting the error:

When I click the error, it takes me back to the Grouped Rows section of my code.

Below is my code. Any idea what I could be tripping up on? To my newb eyes, the set of code that creates Total AUM is the same in structure as the one that creates Total Fees, but clearly I'm overlooking something. Happy to post the entirety of the code if that helps (all the other rows). 

#"Grouped Rows" = Table.Group(#"Changed Type2", {"Value", "QtrEndDate"},{

//Create a column called Total AUM - this section of code works great
{"Total AUM", (t)=>
let
#"LeadAdvisor" = Table.SelectRows(t,each [Attribute] = "LeadAdvisor"),
#"LeadAdvisor AUM" = List.Sum(#"LeadAdvisor"[AUM]),
#"Remove LeadAdvisor Clients" = Table.SelectRows(t, each not List.Contains(#"LeadAdvisor"[Client],[Client])),
#"Unpivoted Columns1" = Table.UnpivotOtherColumns(#"Remove LeadAdvisor Clients",
{"Client", "AUM", "Attribute","QtrEndDate", "Value"}, "Attribute.1", "Value.1"),

//Match Sales to Sales%
#"Sales Attrib" = Table.TransformColumns(#"Unpivoted Columns1",{
//Looks like we are splitting off just down to the # in Sales1, Sales2, Sales3
{"Attribute", each Text.Split(_,"s"){1}},
{"Attribute.1", each Text.SplitAny(_,"s%"){1}}}),
AUMs = Table.SelectRows(#"Sales Attrib", each [Attribute] = [Attribute.1]),
#"Sales AUM" = List.Sum
(List.Generate(
()=>[f=AUMs[AUM]{0} * AUMs[Value.1]{0}, idx=0],
each [idx] < Table.RowCount(AUMs),
each [f=AUMs[AUM]{[idx]+1} * AUMs[Value.1]{[idx]+1}, idx=[idx]+1],
each [f]
))
in
#"LeadAdvisor AUM" + #"Sales AUM", Currency.Type
},

//Create a second column called Total Fees
{"Total Fees", (t)=>
let
//return a table where the Attribute = "Lead Advisor" - essentially filtering the table
#"LeadAdvisor2" = Table.SelectRows(t,each [Attribute] = "LeadAdvisor"),
//add up values from the newly-created table
#"LeadAdvisor Fees" = List.Sum(#"LeadAdvisor2"[Fees paid]),
//return a table where ????
#"Remove LeadAdvisor Clients2" = Table.SelectRows(t, each not List.Contains(#"LeadAdvisor2"[Client],[Client])),
#"Unpivoted Columns2" = Table.UnpivotOtherColumns(#"Remove LeadAdvisor Clients2",
{"Client", "Fees paid", "Attribute","QtrEndDate", "Value"}, "Attribute.2", "Value.2"),

//Match Sales to Sales% - below is the section that is causing the error, b/c when I remove it, I get incorrect values instead of errors
#"Sales Attrib2" = Table.TransformColumns(#"Unpivoted Columns2",{
//Splitting Sales1, Sales2, Sales3 into just numbers
{"Attribute.2", each Text.SplitAny(_,"s%"){1}}}),
//Return rows where Attribute (role) =???
Fees = Table.SelectRows(#"Sales Attrib2", each [Attribute] = [Attribute.2]),
#"Sales Fees" = List.Sum
(List.Generate(
()=>[f=Fees[Fees paid]{0} * Fees[Value.2]{0}, idx=0],
each [idx] < Table.RowCount(Fees),
each [f=Fees[Fees paid]{[idx]+1} * Fees[Value.2]{[idx]+1}, idx=[idx]+1],
each [f]
))
in
#"LeadAdvisor Fees"+ #"Sales Fees" , Currency.Type
}
})
in
#"Grouped Rows"