Call one subroutine from another - excel

Question

I'm trying to unmerge and duplicate data for a folder of xlsx files.
Separately, both macros work as intended. When I combine the macros (through "Call"), it executes but then brings me back to the macro screen. It doesn't give me any errors, but I need to close excel to start over.
I'm guessing the "UnMergeFill" macro isn't playing nice with being opened automatically?
I've tried using "call" and also with just the name of the sub. I've also tried separating the subs into different modules.
Sub AllWorkbooks()
Dim MyFolder As String
Dim MyFile As String
Dim wbk As Workbook
On Error Resume Next
Application.ScreenUpdating = False
With Application.FileDialog(msoFileDialogFolderPicker)
.Title = "Please select a folder"
.Show
.AllowMultiSelect = False
If .SelectedItems.Count = 0 Then
MsgBox "You did not select a folder"
Exit Sub
End If
MyFolder = .SelectedItems(1) & "\"
End With
MyFile = Dir(MyFolder)
Do While MyFile <> “”
Set wbk = Workbooks.Open(Filename:=MyFolder & MyFile)
UnMergeFill
wbk.Close savechanges:=True
MyFile = Dir
Loop
Application.ScreenUpdating = True
End Sub
Call Sub UnMergeFill()
Dim cell As Range, joinedCells As Range
For Each cell In ThisWorkbook.ActiveSheet.UsedRange
If cell.MergeCells Then
Set joinedCells = cell.MergeArea
cell.MergeCells = False
joinedCells.Value = cell.Value
End If
Next
End Sub
'''

Answer 1

Try This:
Sub AllWorkbooks()
Dim MyFolder As String
Dim MyFile As String
Dim wbk As Workbook
On Error Resume Next
Application.ScreenUpdating = False
With Application.FileDialog(msoFileDialogFolderPicker)
.Title = "Please select a folder"
.Show
.AllowMultiSelect = False
If .SelectedItems.Count = 0 Then
MsgBox "You did not select a folder"
Exit Sub
End If
MyFolder = .SelectedItems(1) & "\"
End With
MyFile = Dir(MyFolder)
Do While MyFile <> “”
Set wbk = Workbooks.Open(Filename:=MyFolder & MyFile)
Call UnMergeFill(wbk)
wbk.Close savechanges:=True
MyFile = Dir
Loop
Application.ScreenUpdating = True
End Sub
Sub UnMergeFill(wb As Workbook)
Dim cell As Range, joinedCells As Range
For Each cell In wb.ActiveSheet.UsedRange
If cell.mergeCells Then
Set joinedCells = cell.MergeArea
cell.mergeCells = False
joinedCells.Value = cell.Value
End If
Next
End Sub