Missing Index Items

Well, it gives you the URL right there yeah?

http://evaultsrv01.iprod.local/enterprisevault/download.asp?VaultID=173225416F8C73B41ADE8C0254DCDB65F1110000evault&SavesetID=201401038775847~201312031642270000~Z~C0F8E132943863E0EA5991CEC595F201&Request=NativeItem

So from this you can see the Vault ID: 173225416F8C73B41ADE8C0254DCDB65F1110000evault

Copy that ID, open the Vault Admin Console and hold CTRL-SHIFT and right click "Archives" and select the "Find Archive Or Folder By Id" , paste the ID in there, and it should tell you what Archive it belongs to, and what folder it might be located in.

Then, you can find the archive in the Vault Admin Console, give yourself Read access to the Archive.
Then click the URL, the item will then open in Outlook and you can see the email or the file that it actually is.

You could also go to 
http://evault/EnterpriseVault/Search.asp?advanced

Ensure that Search Attachments is checked.
Select the Archive you just gave yourself permissions to
Then in the "Other Attribute" field, add the word "ssid" and in the Value field paste in 201401038775847~201312031642270000~Z~C0F8E132943863E0EA5991CEC595F201
 

Hit search and you should see the item returned there as well