OWA broken by Chrome


Google’s latest release of their Chrome web browser v37 has deprecated support for the ShowModalDialog API which has caused some OWA and Exchange issues.

Whilst the name ShowModalDialog won’t necessarily mean a lot to most users or seem important what it does in Outlook Web App probably will.  The code behind ShowModalDialog is responsible for some of the features in OWA that require a pop-up window but interestingly enough not all of them.

The features known to be affected are:

  • Opening the Address Book (either via the icon or pressing on To, CC or BCC)
  • Attaching files
  • Inserting pictures


Google claims that the API is not used extensively anymore having been around since early versions of IE and in fact they have only seen it used in 0.006% of pages more recently. Obviously this did not include many OWA or EAC pages, which is maybe not too surprising given that most will be behind corporate firewalls.

OWA 2010 and Exchange 2013 administration are impacted by this change. The simple workaround is to change the browser you use; that said it may not be so straight forward if Chrome has been delivered as part of a standardised package of software by your administrator.

If you are unable or unwilling to change to an alternative browser installing Microsoft Silverlight will resolve the attachments issue. It is likely that a server-side fix will be included in the next rollup update for Exchange 2010 and 2013, but the bad news is that as the last one was in August the next update cycle for Exchange will be November.

There is also an additional bug in Chrome affecting OWA that causes typed hyperlinks to duplicate – Google’s Chrome development team are looking on to this.