-156 RQMRG ERR OUT OF SEQ MSG (Magic xpa 3.x)
The session between the client and the server is no longer synchronized.
A context serving a client received an event from the client containing an unexpected session counter. (Each request from a client must have a session counter equal to the previous session counter + 1.)
The error is usually triggered by communication problems between a client and a server – either on the client's machine/device, oin the network between them, or on the Web server level, leading to exceptions on the client side, while the requests were actually received by the Web server and sent to the Magic xpa server for processing. Such requests, when retried by the client, are rejected by the Magic xpa server (since it expects a request whose session counter is equal to the previous session counter +1, as described above).
Request's Session Counter #X <> Server's Session Counter #Y error