Filling Word forms using Access isn't always working - ms-access

Question

I'm using a code i found online to fill in form fields in a Word document. When i use it on an empty document and add to it a form field, it works. However, when i use it on the form i'm trying to fill nothing happens when i execute the code. I checked the name of the fields in Word and they match the code, i don't know what's wrong.
I also checked the data type in Access and it's not the problem, i don't have access to the code right now but does anyone have any idea of what's causing this?
Edit: Here is a similar code, i don't have access to the exact same one:
Dim appWord As Word.Application
Dim doc As Word.Document
'Avoid error 429, when Word isn't open.
Err.Clear
'Set appWord object variable to running instance of Word.
Set appWord = GetObject(, "Word.Application")
If Err.Number <> 0 Then
'If Word isn't open, create a new instance of Word.
Set appWord = New Word.Application
End If
Set doc = appWord.Documents.Open("C:\Users\" & Environ$("Username") & "\Desktop\Form.doc", , True)
With doc
.FormFields("TextEn").Result = DLookup("[End date]", "[Table1]", "[Table1]![ID Number] =" & [ID2])
.FormFields("TextSt").Result = DLookup("[Starting date]", "[Table1]", "[Table1]![ID Number] =" & [ID2])
.Visible = True
.Activate
End With
Set doc = Nothing
Set appWord = Nothing
Exit Sub
errHandler:
MsgBox Err.Number & ": " & Err.Description

Answer 1

You could try to validate that your dlookup is returning a value with the following:
If DCount("[End date]", "[Table1]", "[Table1]![ID Number] =" & [ID2]) > 0 then
.FormFields("TextEn").Result = DLookup("[End date]", "[Table1]", "[Table1]![ID Number] =" & [ID2])
End If
You would have to do this for each lookup before trying to set your fields.