java-native-access/jna · error · RuntimeException

Unexpected registry type + lpType.getValue() + , expected RE

Error message

Unexpected registry type + lpType.getValue() + , expected REG_SZ or REG_EXPAND_SZ

What it means

A plain java.lang.RuntimeException thrown when the queried registry value's declared type is neither REG_SZ nor REG_EXPAND_SZ. registryGetStringValue only handles string values; a REG_DWORD, REG_BINARY, REG_MULTI_SZ, etc. value is rejected with this message (whose concatenation lists the numeric type code). Note the code builds the message via string concatenation, so the raw numeric type (e.g. 4 for REG_DWORD) appears in the text.

Source

Thrown at contrib/platform/src/com/sun/jna/platform/win32/Advapi32Util.java:773

     *
     * @param hKey
     *            Parent Key.
     * @param value
     *            Name of the value to retrieve.
     * @return String value.
     */
    public static String registryGetStringValue(HKEY hKey, String value) {
        IntByReference lpcbData = new IntByReference();
        IntByReference lpType = new IntByReference();
        int rc = Advapi32.INSTANCE.RegQueryValueEx(hKey, value, 0,
                lpType, (Pointer) null, lpcbData);
        if (rc != W32Errors.ERROR_SUCCESS
                && rc != W32Errors.ERROR_INSUFFICIENT_BUFFER) {
            throw new Win32Exception(rc);
        }
        if (lpType.getValue() != WinNT.REG_SZ
                && lpType.getValue() != WinNT.REG_EXPAND_SZ) {
            throw new RuntimeException("Unexpected registry type "
                    + lpType.getValue()
                    + ", expected REG_SZ or REG_EXPAND_SZ");
        }
        if (lpcbData.getValue() == 0) {
            return "";
        }
        // See comment in #registryGetValue
        Memory mem = new Memory(lpcbData.getValue() + Native.WCHAR_SIZE);
        mem.clear();
        rc = Advapi32.INSTANCE.RegQueryValueEx(hKey, value, 0,
                lpType, mem, lpcbData);
        if (rc != W32Errors.ERROR_SUCCESS
                && rc != W32Errors.ERROR_INSUFFICIENT_BUFFER) {
            throw new Win32Exception(rc);
        }
        if (W32APITypeMapper.DEFAULT == W32APITypeMapper.UNICODE) {
            return mem.getWideString(0);
        } else {

View on GitHub (pinned to d036ad9781)

Solutions

1. Use the type-appropriate getter: registryGetIntValue for REG_DWORD, registryGetBinaryValue for REG_BINARY, registryGetStringArray for REG_MULTI_SZ.
2. Inspect the type first via Advapi32Util.registryGetValue/registryQueryValue and dispatch on it.
3. Recreate the value as a REG_SZ if you own it (reg add /t REG_SZ or PowerShell Set-ItemProperty).
4. Catch RuntimeException from this call and fall back to a generic read + manual conversion.
5. Check whether the 32/64-bit view you query contains a differently typed value than expected (KEY_WOW64 flags).

Example fix

// before
String v = Advapi32Util.registryGetStringValue(WinReg.HKEY_LOCAL_MACHINE, key, "Timeout"); // Timeout is REG_DWORD
// after
Object raw = Advapi32Util.registryGetValue(WinReg.HKEY_LOCAL_MACHINE, key, "Timeout");
String v = (raw instanceof String) ? (String) raw : String.valueOf(raw);

// inspect the value type before choosing a getter
Object raw = Advapi32Util.registryGetValue(root, key, value);
if (raw != null && !(raw instanceof String)) {
    throw new IllegalStateException("Value " + value + " is not REG_SZ (type=" + raw.getClass().getSimpleName() + ")");
}

static boolean isStringRegistryValue(HKEY root, String key, String value) {
    Object v = Advapi32Util.registryGetValue(root, key, value);
    return v instanceof String;
}

try {
    return Advapi32Util.registryGetStringValue(hKey, value);
} catch (RuntimeException e) {
    if (e.getMessage() != null && e.getMessage().contains("Unexpected registry type")) {
        return String.valueOf(Advapi32Util.registryGetValue(hKey, value)); // fallback conversion
    }
    throw e;
}

When it happens

Trigger: Calling Advapi32Util.registryGetStringValue(root/hKey, ..., value) on a value stored as REG_DWORD (4), REG_BINARY (3), REG_MULTI_SZ (7), REG_QWORD (11) or any type other than 1 (REG_SZ) / 2 (REG_EXPAND_SZ); RegQueryValueEx succeeds but lpType.getValue() fails the type check.

Common situations: Registry value type changed by an installer or group policy between app versions; assuming all values under a key are strings; reading a DWORD 'flags' value with the string getter; migrating code from a generic registryGetValue call to the string-specific one.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• LookupAccountNameW was expected to fail with ERROR_INSUFFICI
• Expected GetTokenInformation to fail with ERROR_INSUFFICIENT
• Unexpected registry type + lpType.getValue() + , expected RE
• Unexpected registry type {}, expected REG_SZ
• Unexpected registry type {}, expected REG_BINARY

AI-assisted analysis of java-native-access/jna@d036ad9781 (2026-09-12). Data as JSON: /api/errors/1dc66fbaa7f944a3. Report an issue: GitHub.