This article addresses the `UI_CONFIGURATION_ERROR` encountered in Juniper cRPD, specifically when configuring the local certificate for gRPC services. The error message indicates that the local certificate must be properly defined under the `security certificates local` hierarchy.

Error Message
mustd: UI_CONFIGURATION_ERROR: Process: mustd, path: [edit system services extension-service request-response grpc ssl local-certificate], statement: local-cert-, certificate must be configured under 'security certificates local'

Cause
The error occurs when the local certificate required for the gRPC service is not configured correctly in the Juniper cRPD device.

The above error specifically when configuring the local certificate for gRPC services. The error message indicates that the local certificate must be properly defined under the security certificates local hierarchy.

1. Define the Local Certificate:
   To add your local certificate, enter the following commands in operational mode:

   > configure t
   #set security certificates local <certificate-name> file <path-to-certificate-file>
   #commit
 

   - Replace `<certificate-name>` with a descriptive name for your certificate.
   - Replace `<path-to-certificate-file>` with the full path to your certificate file.
 

2. Configure the gRPC Service:
   Once the local certificate is defined, reference it in your gRPC service configuration:

  #set system services extension-service request-response grpc ssl local-certificate <certificate-name>
  #commit

   - Ensure to replace `<certificate-name>` with the name used in the previous step.
 

3. Verify Configuration:
   After committing the changes, confirm that the configuration is correct with the following command:

  > show configuration system services extension-service request-response grpc

Following these steps should resolve the `UI_CONFIGURATION_ERROR`. The gRPC service will now recognize the local certificate, and the configuration should be applied successfully.

If the issue persists or if you encounter other errors, please consult your Juniper support documentation.