Cant se particles (Realtime button disabled)

Hello, i can not use the REALTIME button. It is unabled, so i can not see fire or smoke in my scene. Does anyone know how can i solve this?

Thank you

Hello! Sorry for your issue! Did this issue occur only in this scene or it happens in all your scene?
Please send us your logs for us to check. You can refer to this post to learn how to collect logs. D5 Support Tool - Get Help / Tech Support - D5 RENDER FORUM