I had the same problem a few week ago you can see my question here. No one was able to help me, I tried different ways to fix it. I finally managed to fix it a few days later by following this link
Copy and paste the following VBA code into any module in the spreadsheet.(Module 1 for me)
Public Sub RenameMSFormsFiles() 
    Const tempFileName As String = "MSForms - Copy.exd"  
    Const msFormsFileName As String = "MSForms.exd"  
    On Error Resume Next 
    'Try to rename the C:\Users\[user.name]\AppData\Local\Temp\Excel8.0\MSForms.exd file  
    RenameFile Environ("TEMP") & "\Excel8.0\" & msFormsFileName, Environ("TEMP") & "\Excel8.0\" & tempFileName 
    'Try to rename the C:\Users\[user.name]\AppData\Local\Temp\VBE\MSForms.exd file  
    RenameFile Environ("TEMP") & "\VBE\" & msFormsFileName, Environ("TEMP") & "\VBE\" & tempFileName 
End Sub  
Private Sub RenameFile(fromFilePath As String, toFilePath As String) 
    If CheckFileExist(fromFilePath) Then 
        DeleteFile toFilePath  
        Name fromFilePath As toFilePath  
    End If  
End Sub  
Private Function CheckFileExist(path As String) As Boolean 
    CheckFileExist = (Dir(path) <> "")  
End Function  
Private Sub DeleteFile(path As String) 
    If CheckFileExist(path) Then 
        SetAttr path, vbNormal  
        Kill path  
    End If  
End Sub
Then call the RenameMSFormsFiles subroutine at the very beginning of the Workbook_Open event.
Private Sub Workbook_Open() 
    RenameMSFormsFiles  
End Sub