The pen has detected an error. T he error could be small, for example the temperature did not rise fast enough or something else is not working. First try unplugging and then re-plug in the pen. Most of the time this will solve the issue. If unplugging and replugging dose not solve the issue and you are still getting the error screen you can try a different plug or outlet. If that still dose not help then please reach out to customer service on email@example.com.