Unpivoting table Power Query and DAX code

Hi Folks 

reaching back out to lbendlin.

You sweated for me on this one a little while ago:

Solved: How to show Staff Capacity against Work by Month - Microsoft Fabric Community

When I add your query and select 'done' it comes up with the table in the 'worked.pbix' you attached to previous post.

I'm just trying to implement now and have got a bit stuck, first issue was the power query didn't work for my source:

Expression.Error: Invalid binary encoding.
Details:
    1a5b9214-7320-41c8-afcb-9660c825e049

I replaced this part of your query highlighted in red:

let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("jdNbb4IwGAbgv9JwresBEL01cUvMku1uF8aLTj5ZM6BLW5b579eC5WjExNAPYngfXsrhELBwSUhIg0XwIdU3ckMGBmlTnc8olSXYCwxTghlhoZ0pjt0Y2fFZQWqXtzzjdiFPiT2+g1HNGbPHPS9At2e3f8eFRzCPYFdEIRUMJRRTdkOyBWUG4Unf5W63lZ/1HM47otg73J8VLFPZIJomqM8PCSaJF+xUKaAhgKqTol5qNOmio9K7lpW3uFvAHy9ECUiBrnKjxx6KSdcIv4KGsfM1jAGJB7hWUqFPldY9gAtd9wTNRnGCFyV/6ypeq7xqQ3e5keXMjhgT1p7gytDCIFneE7BJB11oPGjk8RY2npBMvg/EMy7KMYTilWfsRVFcmrV98EEnDxFi4gmujtOXEtoUXKMfrsxlUoPdmtHoM/Wvnvbjo7n44z8=", BinaryEncoding.Base64),

with what I thought was the source taken from previous queries on the data:

= Source{[Id="1a5b9214-7320-41c8-afcb-9660c825e049"]}[Items]

Thats when I got the expression error.

Please can I get some help with this?

I had 2 follow up queries that I'll ask at the same time now:

1. The slimmed down table I gave in the previous post and which the 'worked.pbix' was generated from- my actual table in the report is bigger- do I need to alter the query to ensure all relevant columns are unpivotted? I have attached a skeleton PBI file which has all the columns in so you can see them- any steer on this welcome)

2. You recommended filtering the DAX outputs you had written "Next step would be to filter a or b with NETWORKDAYS". 

- for a month, or a week, I would need to divide by net working days, but if I needed to check on a single given day, this 'month' logic would not be needed, I am thinking.

- how would the DAX be extended to handle this? I have included the dimdates table in the attached pbix file as well.

Thanks - and let me know if you are on buy me a coffee or equivilant