Runtime error (MissingMemberException): attribute 'DataTree' of 'namespace#' object is read-only

When I run the panel "Adjust load Profile" I am getting the error with the data tree

Runtime error (MissingMemberException): attribute 'DataTree' of 'namespace#' object is read-only

I cannot work out why, it was working previously could someone please explain this runtime error to me.

If you open this Grasshopper file please open the attached Excel file first otherwise there will be no data to input