call DSM_Lock get NullPointerException

[here-mei]

When I call this program, the following methods work without any issues: Twain.setSourceManager(); TwainScanner.getScanner(); TwainSourceManager.selectSource(); TwainSourceManager.openSource(). I can also obtain the state 4 through twainSource.getState(). However, when I call twainSource.enable(); and twainSource.getCapabilities(), a NullPointerException is thrown. After tracing the code, I found that Twain.DSM_Lock returns null, while the passed parameter Pointer is not null. Below is the complete error stack and calling code. Could you please help me analyze where the problem lies and how to solve it?
console printline :
Initializing TWAIN environment...

• Selected source: X2110A
  TWAIN GET: 0f10ffff000000000000000000000000,0f1004007800b4e68701000000000000,null
• Source opened
• Source state: 4
  TWAIN GET: 0f10ffff000000000000000000000000,0f1004008800b4e68701000000000000,null
• Source is online: true
  TWAIN GET: 0301ffff000000000000000000000000,030104009800b4e68701000000000000,null
  General error occurred:
  java.lang.NullPointerException
  at free.lucifer.jtwain.utils.TwainUtils.getINT16(TwainUtils.java:25)
  at free.lucifer.jtwain.variable.TwainContainer.(TwainContainer.java:41)
  at free.lucifer.jtwain.variable.TwainEnumeration.(TwainEnumeration.java:36)
  at free.lucifer.jtwain.TwainCapability.get(TwainCapability.java:94)
  at free.lucifer.jtwain.TwainCapability.get(TwainCapability.java:105)
  at free.lucifer.jtwain.TwainCapability.get(TwainCapability.java:109)
  at free.lucifer.jtwain.TwainCapability.(TwainCapability.java:45)
  at free.lucifer.jtwain.TwainCapability$XferMech.(TwainCapability.java:288)
  at free.lucifer.jtwain.TwainSource.enable(TwainSource.java:339)
  at free.lucifer.jtwain.App.main(App.java:30)

calling code:
public class App {

public static void main(String[] args) {
    try {

        System.out.println("Initializing TWAIN environment...");

// Twain.init();

        TwainSourceManager twainSourceManager = Twain.getSourceManager();
        TwainScanner twainScanner = TwainScanner.getScanner();
        TwainSource twainSource = twainSourceManager.selectSource();
        System.out.println("- Selected source: " + twainSource.getProductName());

        twainSource = twainSourceManager.openSource();
        System.out.println("- Source opened");
        System.out.println("- Source state: " + twainSource.getState());
        System.out.println("- Source is online: " + twainSource.isDeviceOnline());
        twainSource.enable();

        TwainCapability[] twainCapabilities = twainSource.getCapabilities();
        for (TwainCapability capability : twainCapabilities) {
            System.out.println("- Capability: " + capability.cap);
            if (capability.querySupport() == 1) {
                System.out.println("- Support: " + capability.querySupport());
            }
        }


        System.out.println("\nScan completed. Closing resources...");

        Twain.done();
        System.out.println("All resources released.");

    } catch (TwainException e) {
        System.err.println("TWAIN error occurred:");
        e.printStackTrace();
    } catch (Exception e) {
        System.err.println("General error occurred:");
        e.printStackTrace();
    }
}

}