I think the issue here is a root cause problem with the 6.1.* express builds: they embed Tomcat 8 instead of Tomcat 9 (which even the 5.4.* express builds came with). That sure seems a mistake.
I reported this on August 7. It causes an error every time Lucee starts up, due to some class being used that Tomcat 9 handles fine, but 8 can’t handle. See: