Auto fill notworking despite Enable fill handle and cell drag and drop being checked. Also copy/ paste (P) not working either

Hello Attila,

Thank you for posting question on Microsoft Windows Forum!

Well! When both the fill handle and copy/paste functionality fail simultaneously in Excel 2016 despite "Enable fill handle and cell drag-and-drop" being checked, the issue might be caused by sheet grouping/protection, a background clipboard conflict, or an internal property lock set by a macro or add-in.

The suggestion here is to check the Excel title bar at the top. If it says [Group], right-click any sheet tab at the bottom and click Ungroup Sheets. Grouping disables drag-and-drop and limits copy/paste actions across multiple sheets. On the other hand, go to Review > Unprotect Sheet. If cells are locked on a protected sheet, drag-and-drop and pasting will be blocked. Also, try to exit Edit Mode by pressing Esc twice to ensure Excel is not stuck editing a cell or formula.

On the other hand, you can try to clear the Office Clipboard & Conflicting Apps. On the Home tab, click the dialog launcher arrow in the bottom-right corner of the Clipboard group. Click Clear All. Also, close any active screen-capture tools, clipboard manager history apps, or active Remote Desktop/VM sessions, as these hold locks on the Windows System Clipboard.

Another suggestion is to force-enable cell handles via VBA. Since Excel's internal CellDragAndDrop flag can sometimes be disabled by a background script or bad crash, overriding the GUI checkbox. You can press Alt + F11 to open the Visual Basic Editor and press Ctrl + G to open the Immediate Window at the bottom. Paste Application.CellDragAndDrop = True and press Enter. Also paste Application.EnableEvents = True and press Enter. Close the VBA window and test the fill handle again.

Another point worth mentioning here is that third-party COM add-ins might frequently lock Excel's clipboard. You can test in Safe Mode to isolate Add-In conflicts by closing all Excel windows. Then press Win + R, type excel /safe, and press Enter. If AutoFill and Copy/Paste work in Safe Mode, an add-in is causing the lock. Go to File > Options > Add-ins. Select COM Add-ins in the Manage dropdown at the bottom and click Go.... Uncheck all add-ins, click OK, and restart Excel normally to identify the culprit.

You can refer to the following articles for further reference.

• https://support.microsoft.com/en-us/excel/excel-not-responding-hangs-freezes-or-stops-working
• https://support.microsoft.com/en-us/excel/display-or-hide-the-fill-handle

Hope the above information is helpful! If it is. It is appreciated to consider clicking "Accept Answer".