Troubleshooting

Client

java.lang.IllegalArgumentException: Could not find Jetty NPN/ALPN or Conscrypt as installed JDK providers

Perhaps surprisingly, this error may be thrown when connecting to an insecure gRPC server with a client that is configured with TLS enabled.

Server

java.util.concurrent.ExecutionException: io.grpc.StatusRuntimeException: UNAVAILABLE: Failed ALPN negotiation: Unable to find compatible protocol

This may happen when pekko.http.server.preview.enable-http2 is not enabled in the configuration.