Unable to access gRPC service

I am able to access REST service but on same system:port i get

io.grpc.StatusRuntimeException: UNIMPLEMENTED: unknown service api.UserService
at io.grpc.stub.ClientCalls.toStatusRuntimeException(ClientCalls.java:222) ~[grpc-stub-1.13.2.jar:1.13.2]
at io.grpc.stub.ClientCalls.getUnchecked(ClientCalls.java:203) ~[grpc-stub-1.13.2.jar:1.13.2]
at io.grpc.stub.ClientCalls.blockingUnaryCall(ClientCalls.java:132) ~[grpc-stub-1.13.2.jar:1.13.2]
at api.UserServiceGrpc$UserServiceBlockingStub.list(UserServiceGrpc.java:448) ~[classes/:na]

This happens not only for UserService but other services too. Rest service works fine through postman.

my bad :neutral_face: i was using latest gcpc stub for 0.18.0 app server