Most likely some values are null.

try and create a new table without any of the constraints e.g. set all to null and do not have any of the...

can be further simplified
; with mycte as
(SELECT a.MemberID
      , STUFF(
      (SELECT ',' + p.ProgramName
       From MemberProgram...

Can you provide sample tables and data on a consumable format as well as desired output.

although I think I know what you are after the above will not...

Good to know it was my expected "error".

It is a pain for those that don't know better - but in terms of security this is how it should...

you need to change your code to send a string, not a list
something like (untested and not necessarily correct from a syntax point of view)

Cmd.CommandText = "SP_Insert_WC000311A_PremFormData"

can she really not do it or does she just get a warning stating she may not be able to do it? similar to https://sqlstudies.com/2014/07/10/db_ddladmin-and-the-ssms-table-designer/
or does she get a...

always output and visually compare on hex on these cases where it looks the same
(change 500 below as required to hold the content of the fields)

SELECT EmplID

Steve,

As far as I can see its not Luhn 10 checksum but rather processing the numbers at the bottom of a printed cheque/check - https://en.wikipedia.org/wiki/Magnetic_ink_character_recognition

the regex...

I would say your only option is to use a CLR to do it. 
https://www.google.ie/search?q=clr+regex+c%23&oq=regex+clr&aqs=chrome.2.69i57j0l5.5556j0j7&sourceid=chrome&ie=UTF-8 will give you some examples

or eventually R https://www.mssqltips.com/sqlservertip/4748/sql-server-2016-regular-expressions-with-the-r-language/

That is not a local drive then - it is a cluster resource which is not what this thread is all about

Being on the NAS may be the problem - drive should be local, not networked.
This probably should be added as a disk through VM for it to work outside...

Tom what is the SQL version you are using?