About the Environment:
ECP virtual directories point to a VIP with four Multi Role servers behind it. After updating to Exchange 2013 CU15 and updating the Program Files\Microsoft\Exchange Server\V15\ClientAccess\ecp\web.config file with <add key="GetListDefaultResultSize" value="9000" /> on the Multi Role servers and Mailbox servers. I also updated the Program Files\Microsoft\Exchange Server\V15\FrontEnd\HttpProxy\web.config file on the CAS servers.
After the upgrade some users get the following error when selecting an OU "There are more results available than are currently displayed. There are no items to show in this view." Some of the users can only see some of the 2200 OU's. I have confirmed several times that the web.config file is correct, I have cycled all the servers ECP APP pools, I have had the users try different PC's as well as different browsers, they are all in the same group. No change. Any helpful suggestions?