The SDK currently uses Tomcat 7.0.67. This version of Tomcat fails to work when using JARs built for compatibility with Java 9+ and older versions of Java. Having such a module in the classpath results in an SEVERE issue. This results in us being unable to move to more modern versions of some libraries.
Note that this behaviour is fixed in Tomcat 7.0.76 and more recent, so this should be a pretty trivial issue.