KB-1691 Some images in Appian process modeler render as black squares in Internet Explorer

Symptoms

When opening Appian process modeler in Internet Explorer 11, some, but not all, images render as black squares:

Cause

The issue occurs for GIF files served by the web server when the web server is configured to include an X-Content-Type-Options: nosniff header. With the header enabled, the browser cannot detect the correct MIME type of the assets.

The issue is caused by an underlying issue with the assets in the Appian product and has been reported to the Appian Product Team via AN-105088.

Workaround

The recommended workaround is to configure the web server to not serve GIF files from Appian, and instead serve these files from the application server. For Apache Web Server, the Appian documentation includes an example configuration.

Alternatively, the X-Content-Type-Options: nosniff header can be disabled on the web server.

Affected Versions

This article applies to all versions of Appian using a web server and Internet Explorer 11 as a web browser.

Last Reviewed: September 2018