By the end on 2014, till now (and future), Google Chrome could not be no more a browser that will support the actual Exchange 2010/2013/Online OWA feature of Microsoft, because Google, since the release of Google Chrome 37.0, has begun to disable NPIPA plugins in his browser.

In the NPAPI plugins are included Silverlight (on which Exchange Server 2013 and Exchange Online relies for OWA web interface) and Java, so in the future Chrome could be no more usuful for these two web technologies.

In the OWA interface Silverlight is used to manage A: CC: BCC: and attachment buttons (needed for a complete e-mail experience), so this decision to disable, by default, Silverlight in Google Chrome is a great negative hit for OWA users that love to use it on Chrome (or Chromium).

To bypass this behaviour we can use two simple methods: use the chrome://flags/#enable-npapi to re-enable NPAPI plugins and using the Outlook Web App Light (an "old" OWA version that does not use Silverlight technology).

How to Re-Enable NPAPI for Google Chrome

In Chrome's address bar, paste (or type): chrome://flags/#enable-npapi

Find "Enable NPAPI Mac, Windows" in the list, and click "Enable", (Please note: if you don't see this option, it might be that your Chrome version hasn't automatically updated.

Click "Relaunch Now" at the bottom of the page.

Outlook Web App Light

Using Outlook Web App Light when you access on Microsoft Exchange OWA through Google Chrome (or Chromium) will bypass this problem as the "light" portal will not use any plugin such as Silverlight to provide buttons'functionality.

What is NPAPI?

In short, it's the architecture that browser plugins like Google Earth, Google Talk, Silverlight, and Java use to integrate their unique features into browsers.

Why is Chrome ending support for NPAPI?

NPAPI has been the industry-standard cross-browser plugin technology for 20 years, and better, faster, more tightly-secured technology has been developed in recent years which is replacing it. When your version of Chrome updates automatically to version 42 (or above), it will have NPAPI plugin support disabled by default, allowing you to take steps to re-enable it until September 2015.