Microsoft has resolved a known issue that users , as previously closed windows were observed to reappear.
See also: ZeroFont: Tricks Outlook into displaying fake AV scans

“ This issue has been addressed in Version 2309 Build 16827.20130. To install the update immediately, select File > Office Account > Update Options > Update Now ,” Microsoft says in an update to its original August support document, acknowledging the bug .
This issue may occur when using certain SKUs for continuous retail Office, such as Microsoft Office Professional Plus and Office Home and Business, particularly from version 2306 (Build 16529.20154) onwards.
On affected systems, Outlook for Microsoft 365 users encountered dialog boxes with messages such as “Outlook closed while you had items open. Do you want to reopen these items from the last session?” In many cases, when using continuous versions of Office, Outlook options do not present this specific option, known as “Ask me if I want to restore previous items.” This issue makes it impossible for users to configure the settings through the user interface.
The default Outlook window auto-restore option, enabled by default, was released to Microsoft 365 using Outlook for Windows in the Beta Channel 2006 (Build 13006.20002) in June 2020.
“Whether Outlook closed due to an error, a system update, or when you closed it yourself, you will now be asked if you want to reopen previously open windows,” Microsoft describes the feature in a Microsoft 365 Insider communication.
Selecting “Yes” in response to the prompt will re-appear any unexplored emails, open mail windows, scheduled sessions, and open meetings that existed before the program closed with an error during the previous session.
See also: How to sync your Outlook calendar with your iPhone

Provided also by the company a temporary solution for customers who are affected and cannot update Outlook installations immediately. A simple solution they can use is to disable the reload window messages and adjust Outlook settings so that previous items are not repeated each time it opens. In cases where the option to disable the problematic feature is not present in Outlook options, users can set a registry key to disable it.
It is important to note that, due to the periodic nature of this feature, setting this key may not provide a permanent solution and may only partially prevent the reappearance of unexpected messages.
The solution includes a step-by-step process described as follows:
- Start the Registry Editor.
- Create or edit the following DWORD registry value in the specified location.
- Subkey: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Preferences
- DWORD: Reopen the Windows option Value: 1
- Exit the Registry Editor.
- Restart Outlook.
Also, the Outlook team has presented interim solutions for addressing problems that arise after installing the July security updates for Microsoft Office. These issues included blocking certain hyperlinks from Outlook when opening and significant delays when saving attachments to shared network repositories.
See also: The classic Outlook app may be discontinued in the next two years
Additionally, the company announced a solution for a bug that caused slow startup and freezing in Outlook for Microsoft 365 users in June.
It is necessary to emphasize once again Microsoft's dedication to providing genuine and uninterrupted digital experiences for its users. The continuous improvement and regular updating of its software confirm the company's efforts to meet the needs of its users, strengthening its credibility and reputation worldwide. Absolute user satisfaction and avoiding any interruption in services and functions is the goal for Microsoft. By successfully fixing the restart prompt for closed windows in Outlook, Microsoft once again proves its commitment to superior user service.
