Information
package.access grants or revokes access to listed packages during runtime. It is recommended that application access to certain packages be restricted.
This prevents web applications from accessing restricted or unknown packages which may be malicious or dangerous to the application.
Solution
Edit $JETTY_BASE/etc/JETTY.properties by adding allowed packages to the package.access list:
package.access = sun.,org.apache.JETTY.,org.apache.coyote.,org.apache.., org.apache.jasper