Remove all named ranges assigned to different workbook - excel

Question

I have a "Save Inputs" macro in a tool I created which copies the main input sheet in order to save the values for later. The macro removes comments and other unnecessary parts of the original sheet. The tool itself has a bunch of range names, and these get copied along with the sheet. I am trying to delete all of them from the saved input sheet, but encountering an error.
Sub SaveProgramData()
Dim SheetCopy As Worksheet
Dim BookCopy As Workbook
Dim nm As Name
Set Analyzer = ThisWorkbook.Worksheets("Program Dashboard")
Analyzer.copy
Set SheetCopy = ActiveWorkbook.Worksheets(1) 'only way to address copy of a sheet created in new wkbk (i think)
Set BookCopy = SheetCopy.Parent
With SheetCopy
'remove comments, buttons, data validation, do some formatting, etc.
End With
For Each nm In BookCopy.Names
nm.Delete 'this results in a runtime error saying the name I entered is not valid
Next
End Sub
I'm confused because I'm not trying to enter a name, just delete them. I'm also open to another method of copying the sheet that won't keep the names.
EDIT: See comment below, the problem is that most of the names were assigned to ranges in the original workbook. Solved by adding additional condition to If statement:
For Each nm In BookCopy.Names
If InStr(1, nm.RefersTo, SheetCopy.Name) > 1 Or InStr(1, nm.RefersTo, ThisWorkbook.Name) > 1 Then 'check for names scoped to copied sheet, or original workbook
nm.Delete
End If
Next nm

Answer 1

You never initialize the Names variable, so it doesn't know what to loop through.
Try this instead:
Create the following Sub:
Sub RemoveNamesFromSheet()
Dim nm As Name
For Each nm In ActiveWorkbook.Names
If InStr(1, nm.RefersTo, ActiveSheet.Name) > 1 Then
nm.Delete
End If
Next nm
End Sub
Then simply replace your loop with RemoveNamesFromSheet
Hope that does the trick!

Answer 2

I think your last for loop should be for nm in BookCopy.Names

Answer 3

I got it working like this:
Sub RemoveNamesFromSheet()
Dim nm As Name
Application.Calculation = xlCalculateManual
For Each nm In ActiveWorkbook.Names
If InStr(nm, "C:\") > 1 Then
nm.Delete
End If
Next nm
Application.Calculation = xlCalculationAutomatic
Calculate
End Sub
It checks the name for the occurrence of "C:\" which is normally the name of another workbook, so all external references are removed. It assumes the workbooks referring to are closed.
You may also replace "C:\" with the filename that you just copied from. Temporarily disabling automatic recalculation speeds up the process dramatically.