VBA error 1004 Sorry, we couldn't find - vba

Question

I've receive the above error for the following code:
Dim location_results As String
location_results = Worksheets("merging").Range("B1").Text 'absorbing the initial computation results folder
file_results = Dir$(location_results & "\" & "*" & NBDID & "*" & ".*") 'checks if there is a file with NBDID in the "location results folder
If (Len(file_results) > 0) Then
Worksheets("list").Range("D" & i).Value = file_results
Else
MsgBox (NBDID & " result not found")
End If
'problem todoB:
lineD:
Dim shortlocation As String
shortlocation = ThisWorkbook.Path & "\megaresults\" & file_results
On Error GoTo lineD
'Workbooks(shortlocation).Open
Set InputFile = Workbooks.Open(FileName:=shortlocation)
'Set InputFile = Workbooks.Open(location_results & file_results)
Set OutputFile = Workbooks.Open(location_merger & file_merger)
On Error GoTo 0
The error is raised on the line:
Set InputFile = Workbooks.Open(location_results & file_results)
and on the line:
Set InputFile = Workbooks.Open(FileName:=shortlocation)
Now googling that error, nearly everyone has an issue that the file they are trying to open is not in the parents-workbook folder, or that they did not preappend their path to the file specification.
I have done that however, and the path is validated, both manually by me checking whether the file is in the folder, as well as with:
If (Len(file_results) > 0) Then
Worksheets("list").Range("D" & i).Value = file_results
Else
MsgBox (NBDID & " result not found")
End If
, the file exists, and the total path, including file name and extention is 222 characters long. It also contains spaces.
But I can't find any reason for it to return as an error. On top of that, the on error goto lineD does not function, it still pops up with a message that does not allow continuing of the code.
Could someone point out my mistake to me, or give me a solution that would work?
Kind regards.