The server and storage agent are not compatible. The storage agent must be at the same version and release as the server. It must also be at the same modification level, or the same modification level minus one. For example, a server at version 5.2.1 would allow connections from a storage agent at version 5.2.1 or version 5.2.0.
If the storage agent and server are not at the same version and release, update the storage agent to the same version and release as the server. Once the storage agent is at the same version and release as the server, upgrade it to either the same modification level or the same modification level minus one.
None.