1. If the machine is stuck, it is recommended to restart the machine. If the battery of the mobile phone is built-in, please press and hold the power button and volume button at the same time for more than 7 seconds to restart the device.
2. If the operation is normal and the mobile phone supports the intelligent manager (or memory manager), please close the automatically running application through the functions of application management and storage in the intelligent manager, delete unnecessary data such as cache, residue and advertisement, and release the storage space.
3. If it is invalid, back up the data (contacts, text messages, photos, etc. ) and try to restore the factory settings.
If the problem still exists, please bring the machine, purchase invoice and maintenance card to the local Samsung after-sales service center, and the engineer will help you reinstall the version of the mobile phone system.