I use Outlook 2013 every day. It has lots of problems that hopefully will be fixed in a future update. One of those problems is that, maybe once every two weeks, the email attachment previewer will suddenly decide not to work for some file types. Today the html previewer isn't working. I have restarted Outlook, but to no avail. I have restarted the machine to no avail. When this occurs, messages that previously did not have the problem will also have the problem, so it's not content, it's state.
The error is,
This file cannot be previewed because of an error with the following previewer: Html Previewer To open this file in its own program, double-click it.
How do I stop this from happening?