Skip to content

Troubleshooting JVM apps

Stuck? Can't find what you need here? If you're a commercial user then you can write to Otherwise feel free to post in the GitHub discussion forum.

Problems loading native libraries

Conveyor can move native libraries out of JARS to ensure a better end-user experience. It's conventional to always try to load native libraries using System.loadLibrary first unpacking bundled native code, but some libraries don't do this.

You have two possible solutions:

  • Set app.jvm.extract-native-libraries = false. This will cause Conveyor to find and sign any native libraries inside the JARs, allowing your app to extract them to the user's home directory or temp directory at startup. It's not ideal because it will litter your user's system with stuff that uninstalls won't clean up, it slows down app startup and it bloats the size of your download. But it is simple for the developer.
  • Provide the right system properties for your third party library to find its native code. You can do it using the special <libpath> token, like this:
app {
    jvm {
        system-properties {
            "my.library.nativePathLib" = <libpath>

It's often worth reporting these bugs to the upstream projects, so they can use loadLibrary first and only try unpacking libraries afterwards. We are collecting such system properties here - why not send us a PR.

"UnsatisfiedLinkError: ... Mapping process and mapped file (non-platform) have different Team IDs ..."

The file identified as being unloadable is probably in a cache or temp location in your home directory.

This error from macOS can occur when using an app on the same machine used to develop it. It's related to the discussion above about native libraries. When app.jvm.extract-native-libraries = false (which is the default when conveyor.compatibility-level >= 7) Java libraries with native components will go back to the regular behavior of extracting their libs at startup to somewhere in the user's home directory (or a temporary directory). During development the library that gets extracted to this cache path will be unsigned, but when you build your app the embedded .jnilib or .dylib file inside the JAR will be code signed with your identity and the operating system expects them to match. If they don't then you'll get this error. This problem is inherent to the way the JVM ecosystem handles native code and Conveyor gives you several options to resolve it.

The best solution is to opt in to native library extraction. This will place native code in the right places inside the Mac app ensuring no conflicts, fast startup time and avoiding problems with GateKeeper. The downside is you may need to set extra system properties to make your Java libraries look in the right place for their native components.

The quickest solution is to delete the file that the error identifies as being unloadable, then run your packaged and signed app. This will replace the cached version with the version from your app, signed by you. This should also work fine whilst developing your app. The problem with this is that if any of your users have two different apps that use the same Java library, then they will fight over the shared cache location and the signature mismatch error may return.

The final solution is to opt out of Apple's library validation feature. This will make the error go away in all cases without needing extra system properties. However, Apple views apps that do this to be less secure than normal and GateKeeper will run extra checks on them, which might cause your app to be blocked. Do it like this:

app {
    mac { 
        entitlements-plist {
            "" = true

Big delta updates

You can make updates faster by using individual JARs as inputs. This will work much better with delta compression (as used by MSIX/AppInstaller on Windows). Note that explicit JPMS modules will be still be bundled into a single modules file, as this can yield better startup times.

JavaFX fails to launch on Windows citing missing dependencies in glass.dll

Upgrade to JavaFX 19 or higher. Earlier versions of JavaFX rely on the Microsoft VC++ runtime DLLs either coming with the JVM or being already installed on the user's system. Depending on what version of Visual Studio was used to compile your JDK distribute, on a clean Windows install the right DLLs may not be available. In JavaFX 19 the right DLLs are bundled in the jmods. See JDK-8281089. Conveyor will warn you if you're using JavaFX older than 19.