Realme C3 RMX2020 Download Not Completed Error Fix | Oppo_Custom.bin Solution

If you’re flashing your Realme C3 RMX2020 and getting the dreaded “Download not completed” or “Oppo_Custom.bin file error”, you’re not alone. This issue commonly appears when flashing MTK-based Realme or Oppo devices using SP Flash Tool or other flashing utilities.

In this guide, we’ll walk you through the step-by-step solution to fix the Oppo_Custom.bin error and successfully flash your Realme C3 firmware — safely and efficiently.

Understanding the Error

The “Download not completed” message usually appears due to:

• Corrupted or mismatched scatter file.
• Incorrect or missing Oppo_Custom.bin partition.
• Firmware not matching your exact device build (region or version).
• Improper Download Agent (DA) file or authentication bypass.

Since Realme and Oppo devices share MTK platforms, the flashing process requires a precise firmware package and correct DA/Authentication settings.

Step-by-Step Fix for Oppo_Custom.bin Error

1. Use the Correct Firmware Package

Download the official or tested Realme C3 RMX2020 firmware from a trusted source like MobiFirms.com.
Make sure the firmware version matches your region and build number (e.g., RMX2020EX_11_A.65).

2. Check for Oppo_Custom.bin File

Inside the firmware folder, locate the Oppo_Custom.bin file.

• If missing, download a fixed firmware or Oppo_Custom.bin patch for your exact model.
• You can find fixed Oppo_Custom.bin files under the “Fixed Firmware” section on MobiFirms.

3. Use Latest SP Flash Tool

Download and install the latest SP Flash Tool v6.x.

• Load the scatter file from your firmware folder.
• In “Download Only” mode, uncheck the “Oppo_Custom.bin” partition if it’s causing the issue.
• Or, replace it with a working file from a fixed ROM package.

4. Apply Correct DA & Auth Files

Use the MTK_AllInOne_DA.bin and auth_sv5.auth provided in your firmware.
If flashing still fails, try using MTK Auth Bypass Tool (e.g., MCT or MTKClient) to disable SLA/DA protection.

5. Reflash and Verify

Once done, click “Download” and connect your Realme C3 in power-off state (no battery if removable).
After flashing completes successfully, reboot and verify your phone boots normally.

Pro Tips for Technicians

• Always use original USB cables and rear USB ports for better flashing stability.
• Disable antivirus and Windows Defender before starting the flash process.
• Keep a backup of your NVRAM/NVDATA to avoid IMEI loss.
• For bootloop or stuck logo issues, perform a factory reset after flashing.

Final Words

The Oppo_Custom.bin error can be frustrating, but with the right firmware and tools, your Realme C3 RMX2020 can be fully restored. Always use 100% tested firmware from MobiFirms.com to avoid incomplete downloads or partition errors.

👉 Download the fixed Realme C3 firmware now and bring your device back to life safely!