The program used to create this object is Outlook

Many Outlook users are facing a number of problems after applying the recent June 2017 security updates.

In one of these issues, when you open an attachment in an email, contact, or task formatted as Rich Text you get the following error:
“The program used to create this object is Outlook. That program is either not installed on your computer or it is not responding. To edit this object, install Outlook or ensure that any dialog boxes in Outlook are closed”

Microsoft has acknowledged the problems and suggested that users make use of the following workarounds until the issue is resolved.

1. Forward the email to yourself and then open the attachments from the forwarded email;
2. Change the email format to HTML, or Text format;
3. Save the attachments to your computer, using one of the following methods, then open them from the saved location:
   - Drag and drop the attachments to your desktop;
   - Go to File -> Save Attachments;
   - Copy and paste the attachment to your computer.


This and other issues caused by the June 2017 updates are detailed in the Outlook known issues in the June 2017 security updates page. Microsoft said they will update this page when fixes are available, so keep an eye on it!