unable to get the currentregion property of the range class

[rhombus4]

On a Userform when I change a combobox, the value gets entered into a cell
This then runs an Advanced Filter, However I keep getting an error 'unable to get the currentregion property of the range class' when it tries to run the Filter

I know the filter works because it runs fine if I run it manually

Sub filter_Test()
Sheet3.Range("A1").CurrentRegion.AdvancedFilter Action:=xlFilterCopy, _
    CriteriaRange:=Sheet2.Range("T1:T2"), _
      CopyToRange:=Sheet2.Range("H6")

End Sub

But when I try and Run it from Combobox1_Change I get the error
I also get the Same error if I try Debug.Print sheet3.Range("A1").CurrentRegion.Address

Private Sub combobox1_Change()
Sheet3.Range("A1").CurrentRegion.AdvancedFilter Action:=xlFilterCopy, _
    CriteriaRange:=Sheet2.Range("T1:T2"), _
      CopyToRange:=Sheet2.Range("H6")

 

[rhombus4]

Think it must be to do with Rowsource Somehow

Full user code is below. It populates ComboBox ok, but when a Selection in ComboBox is Selected that's when I get the error??

Private Sub UserForm_Initialize()
Sheet2.Range("T2").ClearContents

Sheet3.Range("A1").CurrentRegion.AdvancedFilter Action:=xlFilterCopy, _
    CriteriaRange:=Sheet2.Range("T1:T2"), _
      CopyToRange:=Sheet2.Range("H6")

Me.ComboBox1.RowSource = "combo1Range"

End Sub

Private Sub combobox1_Change()
Sheet2.Range("T2").Value = Me.ComboBox1.Value

Sheet3.Range("A1").CurrentRegion.AdvancedFilter Action:=xlFilterCopy, _
    CriteriaRange:=Sheet2.Range("T1:T2"), _
      CopyToRange:=Sheet2.Range("H6")

End Sub