JNI method that crashes

not_working.m

JNIEXPORT jstring JNICALL Java_ca_weblite_mactools_Sandbox_saveDialog
(JNIEnv *env, jobject jthis, jstring title, jstring extension){
    JNF_COCOA_ENTER(env);
    jstring path;
    //@autoreleasepool {
        
        NSString *cocoaExtension = JNFJavaToNSString(env, extension);
        
        NSSavePanel *panel = [NSSavePanel savePanel];
        NSArray *types = [NSArray arrayWithObjects: cocoaExtension,nil];
        [panel setAllowedFileTypes: types];
        [panel setCanSelectHiddenExtension:TRUE];
        [panel setExtensionHidden:TRUE];
        [panel setTitle: JNFJavaToNSString(env, title)];
        if ( [panel runModal] == NSFileHandlingPanelOKButton ){
            NSURL * out = [[panel URL] filePathURL];
            NSString *outStr = [out path];
            const char *cString = [outStr UTF8String];
            path = (*env)->NewStringUTF(env, cString);
            
        } else {
            path = NULL;
        }
        
        
        
        
    //}
    
    return path;
    JNF_COCOA_EXIT(env);
    
    
}

working.m

JNIEXPORT jstring JNICALL Java_ca_weblite_mactools_Sandbox_saveDialog
(JNIEnv *env, jobject jthis, jstring title, jstring extension){
    //JNF_COCOA_ENTER(env);
    jstring path;
    @autoreleasepool {
        
        NSString *cocoaExtension = JNFJavaToNSString(env, extension);
        
        NSSavePanel *panel = [NSSavePanel savePanel];
        NSArray *types = [NSArray arrayWithObjects: cocoaExtension,nil];
        [panel setAllowedFileTypes: types];
        [panel setCanSelectHiddenExtension:TRUE];
        [panel setExtensionHidden:TRUE];
        [panel setTitle: JNFJavaToNSString(env, title)];
        if ( [panel runModal] == NSFileHandlingPanelOKButton ){
            NSURL * out = [[panel URL] filePathURL];
            NSString *outStr = [out path];
            const char *cString = [outStr UTF8String];
            path = (*env)->NewStringUTF(env, cString);
            
        } else {
            path = NULL;
        }
        
        
        
        
    }
    
    return path;
    //JNF_COCOA_EXIT(env);
    
    
}