Run time error Library not registered while opening a .doc file - vba

Question

I created a macro in excel vba to process a list of file that I need to copy from a "source path" to a "target path". When copied I also need to remove the protection of the .doc file.
Everything is working perfectly fine but only on my station. When I try it on two others stations I get the following error message:
"Run time error '2147319779 (8002801d)'
Automation error
Library not registered"
Here's what I already checked: I've checked for the VBA references in Excel and Word and they are the same.
From what I can found on other forums it could be some hexkeys problem, but I'm so afraid of playing into this, and also the solution that was proposed wasn't working (I couldn't find the appropriate reg key on the problem station).
I also tried adding some delay, but still no luck
Here's my code below
Sub copy_file_and_unprotect()
Dim ws As Worksheet
Dim wb As Workbook
Dim original_name As String
Dim copied_name As String
Dim WdApp As Object
Dim source_path As String
Dim target_path As String
Dim pwd As String
Set wb = ThisWorkbook
Set ws = wb.Worksheets("Liste de vérification") 'where the original folder is stored
target_path = ws.Cells(1, 6) & "\Sections de devis type"
Set ws = wb.Worksheets("Nom des divisions")
source_path = ws.Cells(4, 5) 'where the file will be copied
pwd = "cimaqc123" 'password to unprotect the file
Set wb = ThisWorkbook
Set ws = wb.Worksheets("Plan de travail")
lig = 11
col = 26
Set WdApp = CreateObject("Word.Application")
While ws.Cells(lig, col) <> "" 'loop to copy & unprotect a list of file
num_sec = ws.Cells(lig, col)
nom_sec = ws.Cells(lig, col + 2)
file_name = num_sec & " - " & nom_sec & ".doc" 'name of the original file to be copied
F = Dir(source_path & "\" & "*.doc") 'loop to search thru the source file for the file "file_name"
Do While Len(F) > 0
If F = file_name Then '
original_name = source_path & "\" & F 'path and name of file to be copied
copied_name = target_path & "\" & file_name 'path and name of new file to be unlocked later on
FileCopy original_name, copied_name 'copying of the file
'-----THIS IS WHERE I GET THE ERROR MESSAGE AFTER THE FOLLOWING LINE-----
Set WdApp = Documents.Open(copied_name)
If Not WdApp.ProtectionType = -1 Then 'unprotect the file
WdApp.Unprotect pwd
WdApp.Close True
Else
WdApp.Close True
End If
GoTo file_copied:
End If
F = Dir()
Loop
file_copied:
lig = lig + 1 'on passe à la prochaine section de devis
Wend
End Sub
Could anyone share some taughts about this? How can I resolve the error message I get?

Answer 1

With the help from #KenWhite here's the updated code with error resolved
Sub copy_file_and_unprotect()
Dim ws As Worksheet
Dim wb As Workbook
Dim original_name As String
Dim copied_name As String
Dim WdApp As Object
Dim WdDoc As Object
Dim source_path As String
Dim target_path As String
Dim pwd As String
Set wb = ThisWorkbook
Set ws = wb.Worksheets("Liste de vérification") 'where the original folder is stored
target_path = ws.Cells(1, 6) & "\Sections de devis type"
Set ws = wb.Worksheets("Nom des divisions")
source_path = ws.Cells(4, 5) 'where the file will be copied
pwd = "cimaqc123" 'password to unprotect the file
Set wb = ThisWorkbook
Set ws = wb.Worksheets("Plan de travail")
lig = 11
col = 26
Set WdApp = CreateObject("Word.Application")
While ws.Cells(lig, col) <> "" 'loop to copy & unprotect a list of file
num_sec = ws.Cells(lig, col)
nom_sec = ws.Cells(lig, col + 2)
file_name = num_sec & " - " & nom_sec & ".doc" 'name of the original file to be copied
F = Dir(source_path & "\" & "*.doc") 'loop to search thru the source file for the file "file_name"
Do While Len(F) > 0
If F = file_name Then '
original_name = source_path & "\" & F 'path and name of file to be copied
copied_name = target_path & "\" & file_name 'path and name of new file to be unlocked later on
FileCopy original_name, copied_name 'copying of the file
'----------------LINE BELOW IS WHERE IT WAS CAUSING PROBLEM -------------------------
Set WdDoc = WdApp.Documents.Open(copied_name) 'line that was add
'Set WdApp = Documents.Open(copied_name) 'line that was removed
If Not WdDoc.ProtectionType = -1 Then 'unprotect the file
WdDoc.Unprotect pwd 'replaced WdApp by WdDoc
WdDoc.Save
WdDoc.Close True
Else
WdDoc.Close True
End If
GoTo file_copied:
End If
F = Dir()
Loop
file_copied:
lig = lig + 1
Wend
End Sub