Using office 365 ProPlus 2016 with EV 10.0.4.1189

Thanks for the input , however that solution didnt appear to work.  Our organization is running the 32 bit version of office Proplus and that Reg key already exists. Upon reinstalling, the vault addin appears in list of outlook addins but the other EV menu options do not exist nor look functional. 

OL 2016 isn't officially supported from what I can tell.  You could try this workaround for OL 2013.  Instead of 15 your 16 in the registry entry.

Problem

The Enterprise Vault client fails to install against Outlook 2013 64-bit (Office365 ProPlus edition)

Cause

This issue occurs due to a missing Outlook 2013 registry key which is used by the Enterprise Vault client installer to determine which version of Outlook 2013 is installed. In addition, this issue only affects Outlook 2013 x64 installations when downloaded via an Office 365 ProPlus subscription.

Note: Microsoft has acknowledged this issue and has committed to fix it in a future release of Outlook 2013.

Solution

Follow these steps to to resolve this issue:

1. Open the Windows registry.
   
   Warning: Incorrect use of the Windows registry editor may prevent the operating system from functioning properly. Great care should be taken when making changes to a Windows registry. Registry modifications should only be carried-out by persons experienced in the use of the registry editor application. It is recommended that a complete backup of the registry and workstation be made prior to making any registry changes.
    
2. Create the following registry key:
   
   Location:
   HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\15.0\Outlook
   
   Name: Bitness
   Type: String
   Value: x64
    
3. Re-install the Enterprise Vault client.
    

Additionally, the Enterprise Vault client will be updated to ensure that it can detect and install correctly when this scenario occurs. This update will be included in the Enterprise Vault 11 release.