'We need to know who to send this to' error when completing a task in Outlook

Symptoms
In Microsoft Outlook 2016 and Outlook 2013, when you click Mark Complete or set the status to Complete and then click Save & Close on a task that was assigned to you, you receive the following error message.

We need to know who to send this to. Make sure you enter at least one name.

After you click OK on the error message, the task is marked complete for you, the task owner is notified that the task was completed and the task is marked complete for the task owner.


Resolution
To fix this issue, follow the steps for your Office version and installation type. See the 'More Information' section to determine whether your Office installation type is Click-to-Run or MSI-based.


Office 2016:

Click-to-Run based Installations:
To fix this issue for an Outlook 2016 Click-to-Run installation, make sure that your Office 2016 Click-to-Run installation is at version 16.0.7070.2022 or a later version. If it is not at this version or a later version, update your Office 2016 installation. To do this, follow these steps. 

  1. Open any Office application, such as Outlook or Word.
  2. Click File, and then click Office Account or Account.
  3. View the version that is listed under Office Updates.
  4. If the version is not at 16.0.7070.2022 or a later version, click Update Options, and then click Update Now.

For more information about update channels for Office 365 clients, see Version numbers of update channels for Office 365 clients.


MSI-based Installations:
To fix this issue, install the August 9, 2016, update for Outlook 2016. For information about this update, click the following article number to view the article in the Microsoft Knowledge Base:

3115440 MS16-099: Description of the security update for Outlook 2016: August 9, 2016


Office 2013:


Click-to-Run based Installations:
To fix this issue, make sure that your Office 2013 Click-to-Run installation is at version 15.0.4849.1003 or a later version. If it is not at this version or a later version, update your Office 2013 installation. To do this, follow these steps. 
  1. Open any Office application, such as Outlook or Word.
  2. Click File, and then click Office Account or Account.
  3. View the Version that is listed under Office Updates.
  4. If the version is not at 15.0.4849.1003 or a later version, click Update Options, and then click Update Now.

    NoteIf you had previously disabled updates, click Enable updates after you click Update Options, and then click Update Now.
For more information about Click-to-Run for Office 2013, see the following article: Update history for Office 2013


MSI-based Installations:
To fix this issue, install the August 9, 2016, update for Outlook 2013. For information about this update, click the following article number to view the article in the Microsoft Knowledge Base:

3115452 MS16-099: Description of the security update for Outlook 2016: August 9, 2016


Workaround
The error message can safely be ignored because the task is still marked as complete for you and the task owner.


More information
To determine whether your Office installation is Click-to-Run or MSI-based, follow these steps: 
  1. Start Outlook. 
  2. On the File menu, click Office Account.
  3. For Office Click-to-Run installations, an Update Options item is displayed. For MSI-based installations, the Update Options item isn't displayed.

    Click-to-Run Office 2016 installationMSI-based Office 2016 installation
    Click-to-Run screen shotMSI screen shot

Properties

Article ID: 3164059 - Last Review: 09/30/2016 20:24:00 - Revision: 3.0

Outlook 2016, Microsoft Outlook 2013

  • KB3164059
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