Users are intermittently prompted for credentials when select some items in Enterprise Vault Search (EVS).

Problem

When using (EVS) with the preview pane turned on and selecting specific items users will be presented with a prompt for credentials. This issue may appear intermittent as the issue only occurs with specific emails. Select the 'Cancel' button will allow the user to continue using (EVS). The issue may occur with Enterprise Vault 10 or 11.

Error Message

Review of the IIS logs may show the following one or more times. This will depend on the number of attachment in the message that cause this issue:


2017-02-04 22:17:31 ::1 GET /EnterpriseVault/Download.asp VaultID=1AEEAA71703C0FC478C9AC25B390D98F41110000ev-exch.EV.Local&SaveSetID=%232%241CC5CC3BDCC5AD948824F38EB4B8FCDE81110000ev-exch.EV.Local&Format=NATIVE&AttachmentId=3 80 - ::1 Mozilla/5.0+(compatible;+MSIE+10.0;+Windows+NT+6.2;+WOW64;+Trident/6.0) http://localhost/enterprisevault/Search/ContentView.aspx?snum=2&pvid=1CC5CC3BDCC5AD948824F38EB4B8FCDE81110000ev-exch.EV.Local&vid=1AEEAA71703C0FC478C9AC25B390D98F41110000ev-exch.EV.Local&aid=0&ft=Inbox&tof=300&it=IPM.Note&b=1&vmtp=EXCH&at=&lng=en-US&dtFt=M/d/yyyy&tmFt=H:mm&dtyp=MSG&sId=tgwqcplcdd2y2f4vrm2ac51x&isEa=0 401 2 5 10

A fiddler trace may show the following for each attachment in the message exhibiting the issue:

401 http://localhost/EnterpriseVault/Download.asp?VaultID=1AEEAA71703C0FC478C9AC25B390D98F41110000ev-exch.EV.Local&SaveSetID=%232%241CC5CC3BDCC5AD948824F38EB4B8FCDE81110000ev-exch.EV.Local&Format=NATIVE&AttachmentId=2

 

Cause

The issue is caused by a security setting in the web.config file of the EVSearchClient that is needed for Internet Explorer 9 and earlier. As Internet Explorer 10 and later uses a different security mechanism enabling this setting is not needed and can be turned off.

 

Solution

To resolve this issue for Internet Explorer 10 or 11 perform the following:
 

To configure Enterprise Vault Search for use in Forefront TMG and similar environments

1. Locate the following file on the Enterprise Vault server:

   C:\Program Files (x86)\Enterprise Vault\EVSearch\EVSearchClient\Web.config

2. Open the file in a text editor such as Windows Notepad.

3. Find the following line, and change the value from 1 to 0:

   <add key="UseRestrictedSecurity" value="1"/>

   A value of 1 enforces the security restrictions, whereas 0 relaxes them.

4. Save and close the file.