A1601_11_A.30_171208_7.1.2_OTA.zip (approx. 1.8 GB)
Enter recovery again and perform a factory reset / wipe data . Then reboot. Oppo F1s Firmware Download 7-1-2
Download MTK USB Drivers (v4.0 or newer) and SP Flash Tool v5.1924 for MediaTek-based Oppo F1s. A1601_11_A
If you just want to fix a software bug and stay on the official software, you can find the Official Oppo Firmware for a standard "clean" install. Oppo F1s Firmware Download 7-1-2
: Install a tool like TWRP to manage partitions.