Macro treats single cell as range - excel

Question

In my code, I get runtime error 1004, "unable to set the Locked property of the Range class" every time if I change BX cell value from unlocked to any other. If I change any other value to unlocked code runs good. However, even if C column cells weren't previously merged the error occurs. Also, even if C cells where previously merged, they should be unmerged by Target.Offset(0, 1).Value = "0" this line, which calls second condition in my function. Why I'm getting this error?
Option Explicit
Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range)
Dim pass As String
pass = "" 'set the password. Otherwise, protection/unprotection is done without a pass
If Not Intersect(Target, Range("B14:B50")) Is Nothing And Sh.Name <> "Dane" Then
If Target.Cells.Count > 1 Then Exit Sub
ActiveSheet.Unprotect pass
If Target.Value = "Unlocked" Then
Target.Offset(0, 1).Locked = False
Else
Target.Offset(0, 1).Value = "0"
Target.Offset(0, 1).Locked = True
End If
ActiveSheet.Protect pass
End If
If Not Intersect(Target, Range("C14:C50")) Is Nothing And Sh.Name <> "Dane" Then
Dim i As Long
Dim rng As Range
Application.DisplayAlerts = False
Application.EnableEvents = False
ActiveSheet.Unprotect pass
For i = 1 To 8 Step 1
If i <> 6 And i <> 7 And Cells(Target.Row, i).MergeCells Then
Cells(Target.Row, i).UnMerge
End If
Next i
If Target.Value <> 0 Then
Dim cf As Boolean
If Target.Value > 1 Then
For i = 1 To 8 Step 1
If i <> 6 And i <> 7 Then
Range(Cells(Target.Row, i), Cells(Target.Row + Target.Value - 1, i)).Merge
End If
Next i
End If
For i = 14 To 50 Step 1
If Not cf Then
Set rng = Range("A" & i).MergeArea.Resize(, 8)
With rng
.Borders.LineStyle = xlNone
.Interior.Color = RGB(217, 225, 242)
.BorderAround xlContinuous, xlThin, Color:=RGB(142, 169, 219)
End With
Else
Range("A" & i).MergeArea.Resize(, 8).Interior.Color = xlNone
End If
i = (i + Range("A" & i).MergeArea.Cells.CountLarge) - 1
cf = Not cf
Next i
End If
ActiveSheet.Protect pass
Application.EnableEvents = True
Application.DisplayAlerts = True
End If
End Sub

Answer 1

I think, your code problem is the following:
Any change in "C14:C50" range (even done by first event part, a change in range "B14:B50"), will indeed trigger the second event part, which will merge/unmerge ranges as you want. I did not spend to much time to understand if all logic is OK.
The problem is that this second triggered event ends with ActiveSheet.Protect pass.
The first interrupted event does not start from the beginning. It continues from the line where has been stopped. Meaning that the worksheet will not be unprotected in the moment you try locking a cell in C:C column.
In order to solve the problem, please insert the next line:
If ActiveSheet.ProtectContents Then ActiveSheet.Unprotect pass
just before:
Target.Offset(0, 1).Locked = True
The inserted line, will unprotect the sheet in the situation described above, too.