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

I did not select my post with the added registry key as the Answer to this problem (someone else did). That registry key is Microsoft's work around until they release a fix for this problem., which doesn't work for some users.

There are several answers that work for some and don't work for others, but the Answers that work for all are:

1. Reverting to the version of Outlook (2305) before the bad update caused this problem.
2. As Paul from London pointed out by Not keeping your Outlook settings in the cloud (term for on the Mail server). I don't believe the registry key is needed as this is a cloud problem with Outlook. Why? see # 3 below.
3. Delete all emails from the mail server before closing Outlook. I download and keep the emails I want by transferring the emails to a separate Outlook Data file that is keep on my HDD. I delete all other emails and copies of emails I kept from the server so there are no emails left on the server when I close Outlook. I never had even one occurrence of this popup query from Outlook, yet I did get the update that causes problems for other users.

#2 and # 3 above clearly point to the mail server's emails being the "items to be reopened". I believe the message occurs because Outlook is closed before all the mail folders in Outlook have not synchronized with the same folders on the mails server (cloud) and that discrepancy upon opening causes the message to occur.

To test this, I would like someone that gets these messages often to try synchronizing all the folders before closing Outlook and see if that stops the popup query.

To synchronize a folder, just select the folder in the Navigation pane; which will display "Synchronizing Folder Name" at the bottom of Outlook as shown in the image below. Synchronize each folder before closing Outlook.

Unchecking that "Store My Outlook Settings In the Cloud" was one of the very first things I did when I got my (then)new pc back over a year ago and set up Office, and I have verified that that box is still unchecked, and I still get 'occasional' "Reopen Items..." messages when I start Outlook.

Ever since someone tried to file a tax return in my name about 5 years ago, and then 2 years ago tried filing for state unemployment in my wife's name I don't trust ANY piece of personal information to 'The Cloud'. Heck, even just the act of transmitting that kind of data across the ether from my secure storage to their secure storage is open for possible hacking. So, when I found that "Help" won't work in MS Word UNLESS you allow MS to transmit usage data to their servers 'to allow them to make the application better', I was not happy in the least. But, what ya gonna do...?

Didn't work

Well I just did the following back on the 13th July:

#1 Run Outlook as an Elevated Process (i.e. as Administrator) this is so that if Outlook needed to set stuff outside the Users location (i.e. SYSTEM LOCATIONS)#2 Once opened if popup saying closed with open files, then click on NO.

#3 Disable storing the Outlook settings under Cloud storage options shown in the image below:

#4 Run Registry Editor and set (add DWORD 32-bit item with name ReopenWindowsOption if not already there) ReopenWindowsOption and set its value to 1 in the following location: Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Preferences

#5 Close Outlook and Reboot-System just to make sure new settings are loaded up.

To be honest I think it might just be the disabling of Outlook saving its settings on the cloud that was causing this issue, but I thought I would say what I changed just in case it was a combination of what I did as a whole.

If you disable the Cloud settings save you will need to have that Registry Set!

Image of Outlook settings in the cloud:

Image of Registry Editor:

I have not gotten any more of those popups since (almost a month).

I think the issue might be linked to the remote Cloud saving of the settings which is why it would ignore what you had set in the Registry, which is why it needs that registry added when you disable the saving the settings to the cloud.