Oppo R9s Plus Custom Rom Access

This is the first and most crucial step. Without an unlocked bootloader, you cannot modify the system partitions.

Released in late 2016, the Oppo R9s Plus was a behemoth of a device. With a massive 6-inch Full HD display, a robust 4000mAh battery, and the then-flagship Qualcomm Snapdragon 653 processor, it was a premium phablet designed to compete with the biggest names in the industry. It pioneered Oppo’s VOOC flash charging technology and sported a camera co-engineered with Sony that was ahead of its time. oppo r9s plus custom rom

You lost your modem partition. Flash only the "NON-HLOS.bin" from the stock firmware via fastboot using the command: fastboot flash modem NON-HLOS.bin . This is the first and most crucial step