Samsung devices include a Knox security system that detects unauthorized modifications. Unlocking the bootloader and installing TWRP will trip the Knox counter, permanently voiding your warranty and disabling Samsung Pay and Secure Folder. There is no way to reset the Knox counter on most devices, so proceed only if you are willing to accept these consequences.
Ensure your Samsung Galaxy J2 Core has at least . If the phone powers down mid-flash due to a dead battery, the device components could suffer permanent hardware damage. Required Download Links
For J2 Core, TWRP is required to flash any custom ROM or to root via Magisk.
| Source | Status | |--------|--------| | Official TWRP website | (no device page for j2core) | | XDA Developers Forums | Unofficial builds available (e.g., by developer GRIMLOCK or Galaxy-MSM8917 team) | | Telegram groups | Shared TWRP 3.3.1-0, 3.4.0-0 builds |
In TWRP, tap and type yes . This removes encryption. Reboot back into Recovery ( Reboot > Recovery ).