and if that doesn't work:
- Open your "Messages" app
- Click on the "..." in the top right corner
- go to Settings
- Go to Notifications
- Check "Notification preview"
You can see the sender name, text message (SMS) preview on lock screen or status bar (notification panel). To See Message Preview on Lock Screen in HTC One do as follows:
1. Open “Settings” app
2. Tap “Security”
3. Mark “Message notification preview” to show sender and message preview on lock screen and status bar