: The device must be rooted. On U5 binary, this usually requires flashing a custom recovery like TWRP followed by Magisk .
Samsung uses bootloader revision numbers in firmware (e.g., G950NKSU5DUJ2 – the “5” denotes bootloader v5). Once updated to U5, you to U4 or lower. This changes how the nv_data.bin (EFS partition) is encrypted. g950n u5 imei repair z3x