VBA dynamic feed multiple files into current one but error of "Run-rime error 7 out of memory" occurs

Question

Sub CopyFromWorkbook(frombook As String, fromsheet As Variant, fromrange As Variant, tosheet As Variant, torange As Variant, wb As String, clearwhat As Variant)

Dim copyto, copyfrom As Workbook
Dim ref As Range

Set copyto = ThisWorkbook
If Not (IsWorkbookOpen(wb)) Then
Workbooks.Open Filename:=frombook
Else
Workbooks(wb).Activate
End If

Set copyfrom = ActiveWorkbook
Set ref = copyfrom.Worksheets(fromsheet).Range(fromrange)

copyto.Activate
copyto.Worksheets(tosheet).Range(clearwhat).ClearContents
copyto.Worksheets(tosheet).Range(torange).Resize(ref.Rows.count, ref.Columns.count).Value = ref.Value
copyto.Worksheets(tosheet).Calculate

End Sub

I use below code to run dynamic feed and it succeeds. But for a different set of files, it failed. I already adjust for data range.

the error show