You don't need to enable anything. If you have a volume license file and if you have loaded the itext-licensekey-volume dependency, then iText will have automatically enabled this for you.
You will need to contact our sales department. You can fill out an application here.
Don't worry. If your internet connection dropped, then iText will cache all failed requests during its runtime and will try to send them with next event. For the requests to be send over properly you will need to have a connection during the current runtime of your application. Statistics won't be carried over once the application shuts down.
You can use your volume license keys with iText 5, but you won't be able to use the automated mechanism. To keep track of your statistics, you'll need to implement the Counter interface and register it to the CounterFactory.
Non-paying users can use a barebones counting for their projects. It doesn't involve our server, but is a custom implementation of the Counter interface provided by iText. You can set your implementation by calling the following code:
CounterManager.getInstance().register(new SimpleCounterFactory(new CustomCounter()));
CounterManager.GetInstance().Register(new SimpleCounterFactory(new CustomCounter()));
"iText was unable to record your usage information as required by the Capacity Rental License. Please make sure this machine is able to connect to the iText Volume Server. If you keep seeing this warning message, contact our support team. This means that something went wrong while setting up the connection to our servers. Make sure you can make a connection over the internet on the machine you're running your application.
"The 'itext-licensekey-volume' library is required for your license type, but it is missing or outdated. Please add or update this library. If you keep seeing this warning message, contact our support team. You should add the volume license key library to your project. How to do this is described here.