java-native-access/jna · critical · Error

There is an incompatible JNA native library installed on thi

Error message

There is an incompatible JNA native library installed on this system

Expected: <VERSION_NATIVE>
Found: <nativeVersion> (<path>)
To resolve this issue you may do one of the following:
 - remove or uninstall the offending library

What it means

In Native's static initializer, after loading the native dispatch library (jnidispatch), JNA compares the native library's reported version against the Java-side expected VERSION_NATIVE. A mismatch means the wrong jnidisplitch .so/.dll/.dylib is being loaded, so JNA throws a hard Error describing expected vs found versions and the library path.

Source

Thrown at src/com/sun/jna/Native.java:235

        int nativeMinor = Integer.parseInt(nativeVersionParts[1]);

        if(expectedMajor != nativeMajor) {
            return false;
        }

        if(expectedMinor > nativeMinor) {
            return false;
        }

        return true;
    }

    static {
        loadNativeDispatchLibrary();

        if (! isCompatibleVersion(VERSION_NATIVE, getNativeVersion())) {
            String LS = System.lineSeparator();
            throw new Error(LS + LS
                            + "There is an incompatible JNA native library installed on this system" + LS
                            + "Expected: " + VERSION_NATIVE + LS
                            + "Found:    " + getNativeVersion() + LS
                            + (jnidispatchPath != null
                               ? "(at " + jnidispatchPath + ")" : System.getProperty("java.library.path"))
                            + "." + LS
                            + "To resolve this issue you may do one of the following:" + LS
                            + " - remove or uninstall the offending library" + LS
                            + " - set the system property jna.nosys=true" + LS
                            + " - set jna.boot.library.path to include the path to the version of the " + LS
                            + "   jnidispatch library included with the JNA jar file you are using" + LS);
        }

        POINTER_SIZE = sizeof(TYPE_VOIDP);
        LONG_SIZE = sizeof(TYPE_LONG);
        WCHAR_SIZE = sizeof(TYPE_WCHAR_T);
        SIZE_T_SIZE = sizeof(TYPE_SIZE_T);
        BOOL_SIZE = sizeof(TYPE_BOOL);

View on GitHub (pinned to d036ad9781)

Solutions

1. Remove conflicting JNA jars so exactly one version is on the classpath (mvn dependency:tree / gradle dependencies to find duplicates).
2. Delete or update the stale native library found at the path printed in the error message.
3. Upgrade/downgrade the whole JNA dependency so Java and native versions match (e.g. all at 5.x.y).
4. Force the correct native library via jna.boot.library.path or by bundling the native lib inside jna.jar.
5. Set -Djna.nosys=true so JNA does not pick up system-installed copies.

Example fix

// before (pom.xml): two versions
<dependency><groupId>net.java.dev.jna</groupId><artifactId>jna</artifactId><version>4.5.1</version></dependency>
// after: single matching version
<dependency><groupId>net.java.dev.jna</groupId><artifactId>jna</artifactId><version>5.13.0</version></dependency>

// before touching JNA, verify one consistent version is on the classpath
ClassLoader cl = Native.class.getClassLoader();
try (var stream = cl.getResources("com/sun/jna/Native.class")) {
    while (stream.hasMoreElements()) {
        System.out.println(stream.nextElement()); // multiple URLs => version conflict
    }
}

boolean jnaVersionConsistent() throws IOException {
    var e = Native.class.getClassLoader().getResources("com/sun/jna/Native.class");
    int count = 0;
    while (e.hasMoreElements()) { e.nextElement(); count++; }
    return count == 1;
}

try {
    Class.forName("com.sun.jna.Native", true, Native.class.getClassLoader());
} catch (ExceptionInInitializerError e) {
    throw new IllegalStateException(
        "JNA native/Java version mismatch: " + e.getCause().getMessage()
        + " - fix classpath or remove stale libjnidispatch", e);
}

When it happens

Trigger: Class-initializing com.sun.jna.Native when an older/newer libjnidispatch.so (or jnidispatch.dll) from a different JNA release is found on java.library.path, bundled in the OS, or extracted from a stale jna.jar — getNativeVersion() != VERSION_NATIVE.

Common situations: Multiple JNA jars on the classpath (different versions in app and dependency tree); a system-installed JNA native library shadowing the bundled one; upgrading the Java JNA jar without updating the native library deployment; fat jars with stale extracted natives.

Understand the failure class

Background: "not installed", "pip install", "required for": how missing-dependency errors surface across open-source libraries — this error's family across 34 libraries.

Related errors

• JNA: Problems loading core IDs: %s
• Error looking up CallbackProxy.callback() method
• Error loading DLLCallback class
• Invalid library name "<libname>"
• <libname> does not implement an interface: <interfaceClassNa

AI-assisted analysis of java-native-access/jna@d036ad9781 (2026-09-12). Data as JSON: /api/errors/71f2fe648962ef31. Report an issue: GitHub.