Excel Worksheet_change event no longer firing - events

Question

I dont know when this stopped working to be frank but not long switched to using Office 2016. Either way now a VBA event that previously was firing is not now doing so. At least it does not stop at the first position in the sub where I can set a breakpoint.
There is no use of EnableEvents in this project or other open project, and where the event previously fired, the process reformatting the active cell and another, now it does nothing.
Any help most appreciated!
Public Sub Worksheet_Change(ByVal Target As Range)
Const STATUSCOL1 = "L"
Const STATUSCOL2 = "M"
Const STATUSCOL3 = "N"
Const STATUSCOL4 = "O"
Const STATUSCOL5 = "P"
Const STATUSCOL6 = "Q"
Const STATUSCOL7 = "R"
Const STATUSCOL8 = "S"
Const ACTIONCOL1 = "NOT IMPLEMENTED"
Dim Cell As Range
Dim ac As String
Dim rgtCellVal As Integer
Set Cell = Target
ac = Split(Cell.Address, "$")(1) 'For Column Letter
'if any changes at all mark colum J in Green
If Target.Cells.Count = 1 Then
'If Cell <> IIf(vOldData = vbNullString, "(Null)", vOldData) Then
If Cell.Value <> vOldData Then
Select Case ac
Case ACTIONCOL1
Cells(Cell.Row, Range("J" & 1).Column).Interior.ColorIndex = 42 'Aqua
Case Else
Cells(Cell.Row, Range("J" & 1).Column).Interior.ColorIndex = 4 'bright green
End Select
End If
End If
'Status
'---------------------------------------------------------------------------------------------------------
'Installed & Active
'I&A with Bugs
'Compromise
'If Required
'NotActivatedOrUsed
'UserBlogUseOnly
'UpdateHold
'------------------------------------------
'Deactivated
'Depricated
'Removed
'Not Installed
'------------------------------------------
'Failed
'Broken but activated
'Broken and deactivated
'------------------------------------------
'Status in question
'Ignore
'N.A.
'Not Actionable
'In Progress
'Review
'ConsiderNew
If ac = STATUSCOL1 Or ac = STATUSCOL2 Or ac = STATUSCOL3 Or ac = STATUSCOL4 Or ac = STATUSCOL5 Or ac = STATUSCOL6 Or ac = STATUSCOL7 Or ac = STATUSCOL8 Then
Select Case Cell
Case ""
Cell.Interior.ColorIndex = xlColorIndexNone 'none
Case "Installed & Active"
Cell.Interior.ColorIndex = 43 'Lime
Case "I&A with Bugs"
Cell.Interior.ColorIndex = 36 'Light Yellow
Case "Compromise"
Cell.Interior.ColorIndex = 35 'Light Green
Case "If Required"
Cell.Interior.ColorIndex = 15 'Grey - 25%
Case "UserBlogUseOnly"
Cell.Interior.ColorIndex = 15 'Grey - 25%
Case "UpdateHold"
Cell.Interior.ColorIndex = 46 'Orange
'------------------------------------------
Case "NotActivatedOrUsed"
Cell.Interior.ColorIndex = 15 'Grey - 25%
Case "Deactivated"
Cell.Interior.ColorIndex = 15 'Grey - 25%
Case "Depricated"
Cell.Interior.ColorIndex = 37 'pale blue
Case "Removed"
Cell.Interior.ColorIndex = 41 'Light blue
Case "Rejected"
Cell.Interior.ColorIndex = 41 'Light blue
Case "Not Installed"
Cell.Interior.ColorIndex = 37 'pale blue
'------------------------------------------
Case "Failed"
Cell.Interior.ColorIndex = 3 'Red
Case "Broken"
Cell.Interior.ColorIndex = 3 'Red
Case "BrokenButDeactivated"
Cell.Interior.ColorIndex = 37 'pale blue
'------------------------------------------
Case "StatusInQuestion"
Cell.Interior.ColorIndex = 44 'Gold
Case "Ignore"
Cell.Interior.ColorIndex = xlColorIndexNone 'none
Case "N.A."
Cell.Interior.ColorIndex = xlColorIndexNone 'none
Case "Not Actionable"
Cell.Interior.ColorIndex = xlColorIndexNone 'none
Case "In Progress"
Cell.Interior.ColorIndex = 15 'Grey - 25%
Case "Review"
Cell.Interior.ColorIndex = 33 'Sky Blue
Case "ConsiderAlt"
Cell.Interior.ColorIndex = 44 'Gold
Case "------------------------------------------"
Cell.Interior.ColorIndex = xlColorIndexNone 'none
Case Else
Cell.Interior.ColorIndex = 40 'Tan
rgtCellVal = Cell.Offset(0, 1).Interior.ColorIndex
If (Cell = "") And rgtCellVal = 15 Then
Cell.Interior.ColorIndex = 15
End If
End Select
End If
End Sub

Answer 1

I don't have Excel 2016 yet, but in 2007-2013 you can check macro setting under
File --> Options --> Trust Center --> Trust Center Settings... --> Macro Settings
Make sure that Disable all macros with notification or better is selected
If it was an Add-In, I'd say check to the disabled Add-In's, but it doesn't look like one.
Where is the file located? If it's on a network drive does it work when you copy it to a local drive?
If so then, the check the Trusted Documents options under the Trust Center Settings...

Answer 2

Ok I have the answer:
Trust Center. Macro Settings tab. Developer Macro Settings section. Trust Access to the VBA project object model. Tick Yes!