Failure For Next loop and Copy After

Question

in a

For XThis=1 to Application.Sheets.Count

I am changing between to Workbooks and changing the sheet name

The code works and has worked for a year or longer

I made some changed to the "0Gamx" background code so I wanted to change all of them to match

I have over 1000 sheets. When the code gets to about 518 cycles the screen gets garbaged up (after save and re-start Excel the sheets 519 and above are missing the Combo Box and 2 buttons)

and the biggest issue in that on the "0Gamx" sheet their are 2 buttons and 1 combo box which now do not copy, the rest of the sheet and the page code copy just fine (see below)

            Workbooks(OldWb).Worksheets("0Gamx").Activate
            ActiveSheet.Copy After:=Worksheets(Sheets.Count)
            ActiveSheet.name = CurShtName

I have tried this with Excel 2010, 2016 and 2019 all with the same results

about 518 sheets will copy without a problem and after that the above problem happens

Please let me know if you have an answer for this issue