There´s not sound, vibration or notification icon when receiving new message?
I)In the app, click on ‘Inbox’ on the top left, then click ‘More’ to go the feature page. （You can also hold and then swipe right on the conversation page ）. Then click on Settings -> All -> Notification settings -> Notifications (turn on )
II)See device Settings -> Apps/Apps management -> Handcent Next SMS -> Notifications ON.
III)Also check none of the following apps or apps of this nature are interfering.
• IntelliRing (uncheck the box for it to manage notification volume)
• After School
• Light Manager
• Cleanmaster, check quiet notifications is OFF
• General Settings -> Sound & notification -> Advanced options, ensure Less frequent notification sounds is set to Default Behaviour
• Or typically it's another SMS app or Security app (e.g. Textra, Go SMS, Contacts+, Hangouts, Verizon Messages，360 Security etc) interfering.
• Please disable/uninstall updates (typically found in your device Settings -> App Management/Apps etc) or completely uninstall/remove the culprit and Handcent Next SMS should work perfectly!