Unable To Show Thumbnail Renditions In Sites When Installed On Linux (Doc ID 1676172.1)

Symptoms

On : 11.1.1.8.0 version, 12.2.1.0.0 version, WebCenter Sites

When attempting to show thumbnails of searched images in Contributor UI and Sites is installed on Linux, the following error occurs.

ERROR
-----------------------
Initial error is

java.lang.InternalError: Can't connect to X11 window server using 'localhost:0.0' as the value of the DISPLAY variable.
  at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
  at sun.awt.X11GraphicsEnvironment.access$100(X11GraphicsEnvironment.java:52)
  at sun.awt.X11GraphicsEnvironment$1.run(X11GraphicsEnvironment.java:155)
  at sun.awt.X11GraphicsEnvironment.(X11GraphicsEnvironment.java:131)
  at java.lang.Class.forName(Class.java:169)

and then the following errors are thrown

javax.servlet.ServletException: Servlet execution threw an exception
at com.fatwire.auth.RequestAuthenticationFilter.doFilter(RequestAuthenticationFilter.java:198)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
.......................................................................
Caused by: java.lang.NoClassDefFoundError: Could not initialize class sun.awt.X11.XToolkit
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:190)
at java.awt.Toolkit$2.run(Toolkit.java:868)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:860)
at java.awt.Component.getToolkitImpl(Component.java:1225)

Cause

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