Macro VBA, can't get "SaveAs" to function - excel

Question

I have a process that I run on sets of workbooks. I'm trying to modify the filetype when I close the file. I'm trying to tack it onto the end of the process before closing each workbook. Right now, the opened file is in .xlsb. I'm trying to save it in basically any other format (.xsls, etc.)
Whenever I run the Macro the "SaveAs" command errors out. I've tried everything I can think of to have it just save the file with the same name, different filetype, but no luck.
What am I doing wrong?
Application.ScreenUpdating = False
Application.DisplayAlerts = False
Path = ThisWorkbook.Sheets(1).Range("H6")
If Right(Path, 1) <> "\" Then
Path = Path & "\"
End If
wsheet = ThisWorkbook.Sheets(1).Range("F10")
ThisWorkbook.Sheets(3).Range("A2:B20000").ClearContents
OutLn = 2
Line = 1
Do While ThisWorkbook.Sheets(2).Cells(Line, 1) <> ""
OpnFil = ThisWorkbook.Sheets(2).Cells(Line, 1)
Workbooks.Open fileName:=Path & OpnFil, UpdateLinks:=False
ScanLn = 12
Do While ThisWorkbook.Sheets(1).Cells(ScanLn, 5) <> ""
ThisWorkbook.Sheets(3).Cells(OutLn, 1) = OpnFil
Addr = ThisWorkbook.Sheets(1).Cells(ScanLn, 5)
ThisWorkbook.Sheets(3).Cells(OutLn, 2) = Workbooks(OpnFil).Sheets(wsheet).Range(Addr)
OutLn = OutLn + 1
ScanLn = ScanLn + 1
Loop
Workbooks(OpnFil).SaveAs fileName:=Workbooks(OpnFil).GetBaseName, FileFormat:=51
Workbooks(OpnFil).Close
Line = Line + 1
Loop
End Sub```

Answer 1

Backup Workbooks
Use variables to avoid (long) unreadable lines (parameters).
Option Explicit
Sub BackupWorkbooks()
Dim swb As Workbook: Set swb = ThisWorkbook
Dim dFolderPath As String: dFolderPath = swb.Sheets(1).Range("H6").Value
If Right(dFolderPath, 1) <> "\" Then
dFolderPath = dFolderPath & "\"
End If
Dim dwsName As String: dwsName = swb.Sheets(1).Range("F10").Value
Application.ScreenUpdating = False
swb.Sheets(3).Range("A2:B" & swb.Sheets(3).Rows.Count).ClearContents
Dim OutLn As Long: OutLn = 2
Dim Line As Long: Line = 1
Dim dwb As Workbook
Dim dOldName As String
Dim dOldPath As String
Dim dNewPath As String
Dim dAddr As String
Dim ScanLn As Long
Do While swb.Sheets(2).Cells(Line, 1) <> ""
dOldName = swb.Sheets(2).Cells(Line, 1)
dOldPath = dFolderPath & dOldName
Set dwb = Workbooks.Open(Filename:=dOldPath, UpdateLinks:=False)
ScanLn = 12
Do While swb.Sheets(1).Cells(ScanLn, 5).Value <> ""
swb.Sheets(3).Cells(OutLn, 1).Value = dOldName
dAddr = swb.Sheets(1).Cells(ScanLn, 5).Value
swb.Sheets(3).Cells(OutLn, 2).Value _
= dwb.Worksheets(dwsName).Range(dAddr).Value
OutLn = OutLn + 1
ScanLn = ScanLn + 1
Loop
dNewPath = Left(dOldPath, InStrRev(dOldPath, ".") - 1) & ".xlsx"
' Or if you insist:
'dNewPath = dFolderPath & CreateObject("Scripting.FileSystemObject") _
.GetBaseName(dOldName) & ".xlsx"
Application.DisplayAlerts = False
dwb.SaveAs Filename:=dNewPath, FileFormat:=xlOpenXMLWorkbook ' 51
Application.DisplayAlerts = True
dwb.Close
Line = Line + 1
Loop
Application.ScreenUpdating = True
MsgBox "Backups created.", vbInformation, "Backup Workbooks"
End Sub