this.javaSettings in Application.cfc

Code that works in Lucee;

    this.javaSettings = {
        loadPaths = [
            "../../../lib/webauthn4j-core-0.24.0.RELEASE.jar",
            "../../../lib/webauthn4j-util-0.24.0.RELEASE.jar",
            ]
        };

Didn’t work in Boxlang, I had to convert it to:

    this.javaSettings = {
        loadPaths = [
            expandPath("../../../lib/"),
        ]
    };

This is in CommandBox after switching the cfengine from Lucee to Boxlang:

{
    "name":"passwordless",
    "web":{
        "webroot":"src/cfml",
        "directoryBrowsing":true,
        "accessLogEnable":true,
        "maxRequests":30,
        "gzipEnable":true,
        "welcomeFiles":"index.cfm",
        "bindings":{
            "HTTP":{
                "listen":"0.0.0.0:8080",
                "host":"localhost"
            }
        }
    },
    "app":{
        "cfengine":"boxlang"
    },
    "JVM":{
        "javaVersion":"openjdk21_jdk"
    }
}```

Did you install bx-compat?

I did just now, but that does not make a difference.

Sounds like a bug then. You can file a ticket at the [Jira - Welcome](BoxLang Bug Tracker).