This was a frustrating issue to deal with in a large environment, effectively if you open any “Select an Organization Until” window such as when configuring rules for dynamics distribution groups you may see either a small number of OU records or no OU records at all, with the window simply stating “There are no items to show in this view”.

This most often occurs after Cumulative Updates are applied to a server but may be caused by a lack of configuration or a misconfiguration of the Exchange servers and will present as in the image below –

The Solution

The solution is likely to be quite straightforward, if a little frustrating to implement in a large environment.

1. Navigate to any Exchange server and open the Exchange Management Console.
2. Run the following command to get the number of OU’s in the organization.
   • (Get-OrganizationalUnit -ResultSize unlimited).count
3. Navigate to each Exchange 2013/2016 server which hosts the mailbox role and open IIS.
4. Expand Sites in the left-hand navigation.
5. Right-Click the ‘Exchange Back-End’ site then select Explore.
6. Navigate into the ‘ECP’ folder.
7. Open the Web.config file.
8. Just before the closing </appSettings> tag add a new line and enter the following value, replacing the number with a number larger than the count of OU’s in the organisation.
   • <add key=”GetListDefaultResultSize” value=”1800″ />
9. In IIS, Recycle the MSExchangeECPAppPool on each server.

Once this is completed on every Exchange server hosting the Mailbox role the OU picker should then work again.