Communication between the Loader and the database instance takes place through the synchronous exchange of communication packages. Here, the Loader sends the database instance a package with the command that has to be processed to. This is known as a Request. While the database instance processes the command, the Loader waits for the package of the database instance to be returned with the result. This is known as a Receive.
Errors may occur during this process if the connection from the Loader to the database instance is lost or if the database instance is no longer available.
Use the error text to determine why the communication failed. Fix the cause or the error and restart the Loader.