The network was unavailable or unstable when applying plans.

Verify that the network is available and stable, and then try again.

Arcserve UDP can ping the remote node and remote node can ping back Arcserve UDP.

The network Admin$ share of the remote node was not available when Arcserve UDP tried to communicate with the node.

Verify the network Admin$ of the remote node is available and then try again.

The Arcserve UDP Agent (Windows) node could not handle the load when Arcserve UDP tried to communicate with the node.

Verify that the CPU on the remote Arcserve UDP Agent (Windows) node is in a normal state and then try again.

The Arcserve UDP Agent (Windows) service on the remote node was not running when Arcserve UDP tried to communicate with the node.

Verify that the Arcserve UDP Agent (Windows) service on the remote node is running and then try again.

Used a wrong protocol or port to communicate with the node.

Use the right protocol or port to add/update the remote node in the Arcserve UDP node view.

The Arcserve UDP Agent (Windows) service was not communicating properly.

Restart the Arcserve UDP Agent (Windows) service on the remote node and then try again.