OFFICE WEB APP ERROR: SORRY, THERE WAS A PROBLEM AND WE CAN'T OPEN THIS DOCUMENT

Scenario: On SharePoint 2013 platform, I am trying to open Word documents using Office Web Apps. When trying to open it I'm getting the following error.

OWA will work:  https://webapp/sites/subsite/WithoutSpace

OWA will not work:  https://webapp/sites/subsite/With Space

Solution:  Apply the patch that Microsoft has recently released its patch on April 11, 2017. 

Microsoft has recently released its patch on April 11, 2017 for SharePoint on this issue. Apply below patch (be patience if you don't see anything happening on the screen for couple of minutes) on all SharePoint servers only (not OWA ones).

https://support.microsoft.com/en-us/help/3178732/april-11-2017-update-for-sharepoint-foundation-2013-kb3178732

Hope that will help someone.

Source: https://social.msdn.microsoft.com/Forums/office/en-US/bd7da9fb-eff7-418b-9263-c19b25c1b65c/office-web-apps-server-2013-march-2017-update?forum=sharepointadmin