在添加之前，请检查是否存在具有新名称的现有图纸，以避免后续错误。

Option Explicit

Sub createsheet()

   Dim sName As String, ws As Worksheet
   sName = Sheets("user").Range("M42").Value
   
   ' check if already exists
   On Error Resume Next
   Set ws = Sheets(sName)
   On Error GoTo 0
   
   If ws Is Nothing Then
       ' ok add
       Set ws = Sheets.Add(after:=Sheets(Sheets.Count))
       ws.Name = sName
       MsgBox "Sheet created : " & ws.Name, vbInformation
   Else
       ' exists
       MsgBox "Sheet '" & sName & "' already exists", vbCritical, "Error"
   End If
   
End Sub