For safe mode :
Long press on power button
Until you see restart, power off options
Long press on power off option until you see safe mode
Dear Samsung Member,
Greetings from Samsung Customer Support!
We would request you to register your concern in Samsung Members Application. So, that our concern team gets back to you as soon as possible.
Please follow this path to register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback > Error report/Ask questions).
Note. please attach the error log file within 15 minutes of the error occurred.
Thank you for writing to Samsung.
Samsung Customer Support