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

Just so everyone knows:

The procedure to revert to a prior version (any prior version) applies to Microsoft 365, and the C2R versions of 2013, 2016, and 2019 of Outlook. The Outlook versions must be Click-To-Run and will not work for other versions.

That command tells the Client to Run app file on these system to upgrade to the version listed in the command.

To help understand this process here are my instructions oh how to revert to a prior version written in more detail.

Undo an Outlook Update

Note:  This applies to only C2R versions of Outlook.  This includes Microsoft 365 and the C2R versions of 2013, 2016, and 2019.  To see if you have the C2R version: open Outlook, select File > Office Account. Look for C2R or Click-to-Run after the version and build number under About Outlook.

What

A command in an Administrator’s Command window and an Internet connection can cause Outlook to “update” to the build number indicated in the command.  Using the prior version’s build number reverts Outlook to the prior version and “undoes” the update.   

Why

When an update to Outlook (which installs silently) causes problems, you can undo the update and revert to the version you had before the update occurred as a way to get rid of the problem.  Reverting to a prior version and stopping updates avoids the problems and gives Microsoft time to fix the update bug.  After you find out the update has been fixed, then you can resume updates problem free (hopefully).

How

Step 1 - Disable Outlook Updates

• Open Outlook
• Select File > Office Account
• Click dropdown arrow by Update Options
• Select Disable Updates.  This will cause an UAC box to open to authorize this change.  Click Yes to allow the change in settings.

Step 2 - Find Build Number to Revert To

• The command directs Outlook to change its files to match those found in the build number indicated in the command.  In order to revert to the prior version you need the build number for that prior version.  Here’s how to find that build number for the prior version:
• Open Outlook
• Select File > Office Account
• Under About Outlook note your current version and build number
• Click the dropdown arrow for Update Options and select View Updates.  This opens your default browser to a Microsoft Release Notes page with a list of versions for your Outlook.
• Click the version list just below the version you currently have.  The version number is a link to specific details of that version including the build number for that version.
• Make sure you have the right version and if the same version number is listed twice, select the last one released.  To make sure I get the build number correct, I highlight and copy just the number as well as write it down.

Step 3 - Revert to Prior Version

• You must have your PC connected to the Internet.  Close Outlook.
• Open an Administrator Command window by opening a Run box (WinKey + R), enter cmd, press the Ctrl + Shift + Enter keys at the same time, and click Yes to the UAC query box that opens.
• At the prompt enter the following command and press the Enter key: *CD %programfiles%\Common Files\Microsoft Shared\ClickToRun*
• The above command is suitable for copy and paste.  Note the space between CD and %.  This command will change the prompt location to the folder where the OfficeC2RClient.exe application file is kept.  The above command changes the prompt location to the default location on all the versions stated above except 2013 C2R, whose default location is in a different folder.  Search for the folder that contains the OfficeC2RClient.exe file and adjust the command above to change the prompt location to that folder.
• With the prompt location at the folder that the OfficeC2RClient.exe file is located in, enter the following command: OfficeC2RClient.exe /update user updatetoversion=16.0.build number
• The above command is Not suitable for copy and paste.  The build number must be replaced by the actual build number for the version you want.   Notice the 16.0. before the build number.  This is the Office group number which is 16.0 for 365, 2016, and 2019.  For 2013 the group number is 15.0.  Note the period between the group number and the build number.  Example of the command for Outlook 2019 C2R to revert from version 2306 to version 2305 (Build 16501.20210): OfficeC2RClient.exe /update user updatetoversion=16.0.16501.20210
• After pressing the Enter for your command various windows will open as the OfficeC2RClient app gets the files from Microsoft and performs the version placement requested.
• When finished the prompt will return to the same prompt location awaiting your next command.
• Close the Command window.
• Open Outlook and check the version/build in Office Account and you will see the version build you requested.
• You will also see that whatever the last update did, reverting to a prior version has undone what it did.

... I tried your fix to revert to version 2035, even though Outlook 21 was not included in your list of versions, and it did not work ...

Hi Pete James1:

Do you mean that the instructions did not roll back your MS Office 2021 C2R to Version 2305 (Build 16501.20210), or do you mean that the roll back to Version 2305 did not solve your problem with the "Outlook Closed while you had items open. Reopen those items from your last session?" prompt?

Instructions on how to roll back to a previous version of MS Office C2R are also posted in Diane Poremsky's article Uninstall Updates in Office 'Click to Run' on slipstick.com, which includes a link to the companion slipstick YouTube video Rollback to a Previous Version of Office

Diane's instructions were last revised on 27-Sep-2021 and do not specifically mention MS Office 2021 as an applicable product but her 27-Feb-2023 comment #22106 below those instructions indicate they should also work for MS Office 2021 C2R.

As Gregory-Assistance Needed and Drcard:)) both noted, if you are using a retail version of MS Office 2016 C2R or 2019 C2R (and presumably, MS Office 2021 C2R) then temporarily stopping your Office updates (File | Office Account | Update Options | Disable Updates) and entering the command "C:\Program Files\Common Files\microsoft shared\ClickToRun\officec2rclient.exe" /update user updatetoversion=16.0.16501.20210 in an elevated command prompt with Administrator rights should should roll you back to the Version 2305 (Build 16501.20210) released on 13-Jun-2023. Previous version numbers and release dates for retail versions of MS Office 2021 C2R are posted <here>; for MS Office 2016 C2R and MS Office 2019 C2R see <here>.

Dell Inspiron 5584 * 64-bit Win 10 Pro v22H2 build 19045.3208 * Firefox v115.0.2 * Microsoft Defender v4.18.23050.5-1.1.23060.1005 * Malwarebytes Premium v4.5.33.272-1.0.2069 * Macrium Reflect Free v8.0.7279 * Microsoft Office 2019 Home and Business 2019 Version 2306 / Build 16529.20182 C2R

I just disabled the Cloud storage options (Store my Outlook settings in the cloud) along with running it as an elevated (run as Administrator) to make sure any setting is set / created and then closed and run as normal and has been working fine for 3 days so far.

Hello again Great White North,

The instructions did not roll back the previous version. Perhaps I did something wrong.

Thanks for the in-depth article you have sent, I will have a closer look at the suggestions when I get home from work.

Thanks for the post.

Pete.