Keep Getting "Outlook closed while you had items open. Reopen items from last session?" Even Though It's Not True

First - I did NOT select the the addition of that registry key as the "solution" or "answer" to this problem.

This "solution" is Microsoft's official work around until they issue an update that will solve the problem and as you know doesn't work for all users.

For reference, these are the suggestive work arounds:

1)The added ReopenWindowsOption registry key doesn't stop the popup window for all users. BTW: That key was already in the Registry in Outlook version 2305 to store the startup option that the user selected in Outlook's options. The upgrade to version 2306 removed the options and registry key which caused the popup window to start being a problem.

2)Some have suggested that that opening and closing Outlook will stop the popup, but other users say it didn't work for them.

3)Other users say that having Outlook settings to save it settings in the Cloud stops the popup, but there are other users that do not save their settings to the Cloud and do not get the popups indicating that setting may not affect the popup.

4)One method that is 100% effective in solving the popup problem is to stop updates and revert to Outlook version 2305. Wait till Microsoft releases an update that fixes this problem and begin updating again. You must have a Click 2 Run version of Outlook.

5)I have never gotten the popup message when I open Outlook, even after automatic updates. I do not save any Outlook settings to the cloud. I do not keep any emails on the mail server (delete all after downloading). I did not add the registry key after it was removed by the update. I reverted to version 2305 and the registry key was added by the update to a prior version. I then updated to version 2307 (by-passing version 2306) which removes the Startup Options on the General page of Outlook's Options, but the registry key and its setting remain in the Registry.

The choice is yours to try.

Another option that might work is to open Outlook Offline and see if the popup message occurs. After Outlook is open, click the Offline button to toggle to go Online to get your emails. Opening and going online at the same time may be triggering these popup boxes. If you decide to try this, the following link is to the instructions for how to open Outlook Offline/Online.

Open Outlook Offline

Thank you for sharing a solution. Unfortunately, it does not work on my machine. Please see the below screenshots. Do you have any suggestions to resolve the issue on my machine?

Thank you.

This was never a problem until within the last two months (today is 8/18/23). Something caused this issue to arise, probably a Win update. The registry flag does not work for me nor does the trick of opening Outlook twice. I think the only solution will have to come from Microsoft, a coder must look into what triggers this message and what goes wrong to cause it to launch. Along with that, the coder's supervisor should look into what useful purpose the message popup serves in the first place. The simplest answer is for MS to simply delete the code that pops up the message and send out a patch to the zillions of people who have this problem.

I continue to have erratic problems with this goofy 'Reopen...' pop-up message, so I'm not about to further mess things up with finagling registry keys. As I say, too many times I've put my finger in the dike to stop the leak only to find that I've dislodged another pebble that in turn lets loose the small rock that's holding the bigger stone in and... voila, a full deluge.

I added that ' /restore' last week and since then erratic behavior. Last Saturday, Outlook started into a window with no problems (yay!) but then Sunday it remained minimized and I had to click on it again to get into a window. Monday it opened in a window, re-opened (again!) an already opened/read email from the previous day, AND gave me the "Reopen...?" pop-up. Tuesday it opened in a window, no pop-up, no previously read mail - all fine. Wednesday and this morning again it stayed minimized.

Every night before I close Outlook, I do a send/receive and make sure the little message "synchronizing all folders" at the bottom completes/closes. Then I close Outlook. I wait anywhere from 5-15 minutes (Solitaire helps pass the time) and then check Task Manager to make sure Outlook is not still running, then close down my laptop.

It is the peak of lunacy to do the exact same thing and get varying results, but there is a name that describes this - 'chaos', which in physics is defined as "behavior so unpredictable as to appear random, owing to great sensitivity to small changes in conditions".

There is something unstable down there in the coding of Outlook and dmmit, I wish they would fix it.

Restating my conditions of operation: Dell Inspiron 5501 11th Gen i5-11320H; Win 11 Home, v22H2, OS 22621.2134, Experience Pack 1000.22659.1000.0; Outlook 16.0.16626.20170; "Save my settings in cloud" unchecked, Missing Outlook "Startup Options" selections; added ' /restore' to Outlook icon; no registry key changes/deletions/additions.