Attempting to send an email with attachment in Outlook 2016 fails with: “The function cannot be performed because the message has been changed.”

Problem

You’ve received reports from users that they would intermittently receive the following error messages when they send an email with an attachment:

The function cannot be performed because the message has been changed.

The operation failed. The messaging interfaces have returned an unknown error. If the problem persists, restart Outlook.

This item is no longer valid because it has been closed.

The Outlook version installed is Microsoft Outlook 2016 MSO (16.0.4738.1000) and Exchange Server 2019 CU1 is where the mailbox is hosted.

This doesn’t to happen with all attachments and appear to only affect attachments that are several MBs in size (under 1MB appears to work but 3MB+ does not).

Solution

Troubleshooting this issue was difficult as it was not easy to replicate and the event logs did not log any errors but after locating several attachments that didn’t work, it was observed that problematic attachments would cause the Outlook window to hang for several seconds and the Send as Adobe Document Cloud link would appear in the email:

This lead me to believe that it may be a plugin issue so I navigated into the the COM Add-ins window, disabled the Adobe Document Cloud for Microsoft Outlook – Acrobat add-in, tested again and the problem went away:

This environment was undergoing an Exchange 2013 to 2019 migration and this appears to only affect migrated users so our suspicion is that the following Adobe Acrobat DC 19.010.20098 reader needs to be updated:

Attempting to sign into Office 365 https://login.microsoftonline.com/ continuously loops after entering credentials

Problem

You have a new user account that was setup in an on premise Active Directory domain with an Office 365 license but noticed that launching any of this user’s Office applications will attempt to sign into Office 365 with his on premise AD account and would fail to retrieve the license and activate his Office. Reviewing his account on the account on Office 365’s Admin center confirm that he has a valid E3 license assigned to his account:

Attempting to test his account by signing into the portal https://login.microsoft.com:

… cause a constant loop with the as shown in the following 2 screenshots:

We don’t recognize this user ID or password

Be sure to type the password for your work or school account.

Redirecting…

We’re taking you to your organization’s sign-in page.

Attempting to unassigned and reassign E3 license does not correct the issue:

Solution

After trying numerous troubleshooting steps without any luck, what corrected the issue was the following:

1. Unassigned the Office 365 E3 license via the Office 365 admin portal
2. Remove the account from the on premise Active Directory
3. Force DirSync to sync up the on premise AD with the Azure / O365 AD
4. Verify that the account no longer exists on the O365 portal
5. Recreate the account
6. Force DirSync to sync up the on premise AD with the Azure / O365 AD
7. Verify that the account exists on the O365 portal
8. Reassign the Office 365 E3 license

I understand that this probably isn’t viable solution if this is an existing account that has been in use for a long period of time but the situation I was in involved a new account so I was able to perform the above without affecting an existing user.

Disabling “Do Not Send a Response” option for meeting invites in Outlook 2010 and Outlook 2016

I’ve recently been asked by a client whether there was a way to disable the Do Not Send a Response option within Outlook 2010 and Outlook 2016 because the Response column in the View Tracking Status does not get updated unless the user chooses to send a response:

 

After doing a bit of research on forums about this topic, it appears many users have complained about sending a response because it would lead to mailbox clutter for the meeting organizer and the proposed solution is to turn on the Update tracking information, and then delete response that don’t contain comments option in the File > Options > Mail > Tracking settings:

While this helped with encouraging users to send a response, the client still wanted to disable the Do Not Send a Response option and after a bit more digging, I found the solution in this forum post:

https://social.technet.microsoft.com/Forums/office/en-US/5861d690-aae8-4f37-a9e6-687984fb2540/how-to-disable-meeting-response-action-do-not-respond?forum=outlook

The setting to disable the option is in User Configuration > Polices > Administrative Templates > Microsoft Outlook 2010 > Disable Items in User Interface > Custom

Proceed and enable the setting Disable command bar buttons and menu items and then enter the following command bar ID:

• 19987
• 19995
• 19991

Apply this GPO to the user accounts that require this configuration and users should see the following when attempting to accept a meeting:

I’ve also tested this with Outlook 2016 and can confirm that the same settings with the Office 2016 policy templates yield the same result.