Asynchronous data loading mode is enabled by design and by default when you use components from Gantt Chart Light Library. However, some operations, such as LevelResources or SaveProjectXml require that all data is loaded in order to consider the entire project as data source; otherwise, when such operations are executed, they will consider only the actually loaded data until the time they are run.
For example, if you choose to save a project that is still loading, the saved XML file might contain only part of the project data.
To resolve the issues that this behavior may generate, you need to disable the project operations in your application until all data gets loaded completely. To be notified when all data is loaded, simply handle the first AsyncPresentationCompleted event occurrence of the component.
Alternatively, you may disable asynchronous data loading by setting IsAsyncPresentationEnabled property of the component instance to false.