Hi
Here is the details of the blog entry
With regards to the Microsoft Office 365 ProPlus subscription (Outlook 2013 x64).
Cause:
This issue occurs due to a missing Outlook 2013 registry key which is used by the various client software installers 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:
A work-around is to manually create the missing registry key until Microsoft provides a fix.
Create the following registry key:
Location: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\15.0\Outlook
Name: Bitness
Type: String
Value: x64
regards
Derek