The error 50051-MW1 occurs in the event of a time-out when attempting to communicate with the PlayStation Network matchmaking server. This kind of error is caused by temporary communication failure such as communication equipment malfunction, downtime with PlayStation Network, server maintenance, and/or server congestion.
To troubleshoot this issue, please visit the following Network/Connection Troubleshooting Guide.
If the issue persists, we recommend contacting your Internet Service Provider for additional assistance with your network environment.