#Name? error for TextJoin UDF

[Mati44]

I have this TextJoin macro in excel 2007. I used this UDF =TextJoin(...) to join cells on a specific condition like this:

=TEXTJOIN(",",TRUE,IF(A6:E6<=7,A6:E6,""))
=Iferror(TEXTJOIN(",",TRUE,IF((A6:E6<=18)*(A6:E6>=12),A6:E6,"")),"")
=TEXTJOIN(",",TRUE,IF((A6:E6>=10),A6:E6,""))

It worked for me at the beginning, I got my results, then a little while later, all cells showed #Name? error.
I didn't change the code, or data. and I can't figure out a way to solve the problem.
Now when I type =Textjoin in a cell, it doesn't even appear there as a function.

Here is the code I used:

Function TextJoin(delim As String, skipblank As Boolean, arr)    Dim d As Long
    Dim c As Long
    Dim arr2()
    Dim t As Long, y As Long
    t = -1
    y = -1
    If TypeName(arr) = "Range" Then
        arr2 = arr.Value
    Else
        arr2 = arr
    End If
    On Error Resume Next
    t = UBound(arr2, 2)
    y = UBound(arr2, 1)
    On Error GoTo 0


    If t >= 0 And y >= 0 Then
        For c = LBound(arr2, 1) To UBound(arr2, 1)
            For d = LBound(arr2, 1) To UBound(arr2, 2)
                If arr2(c, d) <> "" Or Not skipblank Then
                    TextJoin = TextJoin & arr2(c, d) & delim
                End If
            Next d
        Next c
    Else
        For c = LBound(arr2) To UBound(arr2)
            If arr2(c) <> "" Or Not skipblank Then
                TextJoin = TextJoin & arr2(c) & delim
            End If
        Next c
    End If
    TextJoin = Left(TextJoin, Len(TextJoin) - Len(delim))
End Function

Any suggestions to solve the problem are greatly welcomed. thanks.