MongoDB Java Driver: The type com.mongodb.client.model.InsertOneOptions cannot be resolved. It is indirectly referenced from required .class files

Based on the code you've provided, I suggest that you should add the server name and the port when creating the MongoClient instance like this:

public Mongo() {
    String serverName = ""; //Usually it's 'localhost'
    String serverPort = ""; //Usually it's '8080'
    try {
        mongoClient = new MongoClient(serverName, serverPort);
        db = mongoClient.getDatabase("IFHKServer");
    } catch (MongoClientException e) {
        System.err.println("Error connecting to MongoDB Client.");
        Logger.getLogger(Mongo.class.getName()).log(Level.SEVERE, null, e);        }
}

Also, consider creating a method that will terminate the connection to MongoDB instance, when you are finished inserting new documents.

public final void closeMongoDBConnection() {
    try {
        mongoClient.close();
    } catch (Exception e) {
        System.err.println("Error in terminating connection");
        Logger.getLogger(Mongo.class.getName()).log(Level.SEVERE, null, e);
    }
}

The insertion code seems good as far as I can see.

General tips:

• If you are attempting to insert, update or delete documents in MongoDB, always surround your code into try-catch blocks.
• Do not omit the public/private/protected identifier from your methods/class fields, unless you want to restrict using your code only to your class/package. Assuming that your project includes classes in other packages that employ the code in Mongo class, declaring a method with no modifier permits the use of it outside the package that this class belongs to.
• Avoid using hardcoded names for things that are anytime subject to change, like the name of your collection or a field in a document. You can transfer all these values into an external .properties file and read them using the Properties class. In that way your code will be more flexible in external changes, without rebuilding your entite project.

EDIT

Aside from the BSON Library, you should have the following three:

• mongodb-driver-3.0.4.jar
• mongodb-driver-async-3.0.4.jar
• mongodb-driver-core-3.0.4.jar