Information
The Error Report Valve is a simple error handler for HTTP status codes that will generate and return HTML error pages. It can also be configured to return pre-defined static HTML pages for specific status codes and/or exception types. Disabling showServerInfo will only return the HTTP status code and remove all CSS from the default non-error related HTTP responses.
Solution
As a privileged user on the Tomcat server:
Edit the $CATALINA_BASE/conf/server.xml file.
Create or modify an ErrorReportValve <Valve> element nested beneath each <Host> element.
EXAMPLE:
<Host name='localhost' appBase='webapps'
unpackWARs='true' autoDeploy='false'>
...
<Valve className='org.apache.catalina.valves.ErrorReportValve'
showServerInfo='false' />
...
</Host>
Restart the Tomcat server:
sudo systemctl restart tomcat
sudo systemctl daemon-reload