When adding an SRX cluster to Juniper Security Director, it fails due to an RPC error.

Error message:

Reason: Sync Config : rpc error: code = Unknown desc = invalid character 'm' looking for beginning of value

In this particular case, the SRX IDP sensor settings set resource limits, tune performance settings such as memory and session usage, and define how the sensor interacts with other systems to monitor and mitigate network threats. For instance, the Juniper Security Director is not able to properly manage the device and fails during the discovery process.

The lines of configuration need to be removed from the device for the device discovery to be successful:

delete security idp sensor-configuration