运行时错误“1004”：但停在中间？

不知道我在做什么错。 它工作正常，但当它打开104 xlsm文件，然后我收到

运行时错误“1004”：对象“工作簿”的方法“打开”失败。

Sub OpenAllWorkbooks() If MsgBox("Please have all other excel files closed before running macro. Would you like to continue?", vbYesNo) = vbNo Then Exit Sub 'Optimize Macro Speed Application.ScreenUpdating = False Application.EnableEvents = False Application.Calculation = xlCalculationManual 'Step 1:Declare your variables Dim MyFiles As String Dim count As Integer Dim Worksheet As Worksheet count = 16 'Step 2: Specify a target folder/directory, you may change it. MyFiles = Dir("\\My Documents\ Dropbox\*.xlsm")) Do While MyFiles <> "" count = count + 1 'Step 3: Open Workbooks one by one Workbooks.Open "\\My Documents\ Dropbox\" & MyFiles 'run some code here Sheets("Data").Visible = True Sheets("Data").Select Range("A2").Select Range(Selection, Selection.End(xlToRight)).Select Selection.Copy Windows("Master Database.xlsm").Activate Range("B" & count).PasteSpecial xlPasteValues Application.CutCopyMode = False Range("B14").Select ActiveWindow.ActivateNext Sheets("Data").Visible = False Sheets("Instructions").Select Range("F9").Select ActiveWorkbook.Save ActiveWorkbook.Close 'Step 4: Next File in the folder/Directory MyFiles = Dir Loop Windows("Master Database.xlsm").Activate ResetSettings: 'Reset Macro Optimization Settings Application.EnableEvents = True Application.Calculation = xlCalculationAutomatic Application.ScreenUpdating = True