If you're open to a VBA suggestion, this code that
MARK858 over at MrE posted a few years ago has worked for me in the past.
Don't know if it will for you but might be worth giving it a try.
Code:
Sub LoseThatWeightx()
Dim xx As Long, LastRow As Long, LastCol As Long
Application.ScreenUpdating = False
With ActiveSheet
LastRow = .Cells.Find(What:="*", After:=.Range("A1"), LookIn:=xlValues, _
LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlPrevious).Row
LastCol = .Cells.Find(What:="*", After:=.Range("A1"), LookIn:=xlValues, _
LookAt:=xlPart, SearchOrder:=xlByColumns, SearchDirection:=xlPrevious).Column
.Range(.Cells(1, LastCol + 1), .Cells(Rows.Count, Columns.Count)).Delete
.Range(.Cells(LastRow + 1, 1), .Cells(Rows.Count, Columns.Count)).Delete
End With
xx = Application.ActiveSheet.UsedRange.Rows.Count
Application.ScreenUpdating = True
End Sub