You might notice that your web browser sometimes displays icons in the address bar or with the name of a bookmark in the bookmarks list.
The messages you are seing are because the web browser is attempting to download the icon file if it is available.
I do not know which JBoss version you are using or how your application is structured but basically you need to place a file called favicon.ico in a location that will allow it to be downloaded using the URL the web browser is using.
I have a favicon.ico in my root of the web app for which I am seeing the error messages. I understand the concept of what it is. I just do not understand where in the JBOSS folders I need to place the file. Placing it in the root of the web app does not fix the problem.
Find the ROOT.war folder in the tomcat deployment and place favicon.ico there. Example folder for JBOSS 3.2.6: