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Why is the USB file transfer option greyed out on my OnePlus 15?
Diagnosing the Connectivity Lockout
A OnePlus 15 user recently reported a critical interface issue where the “USB File Transfer” option became inaccessible. The text appeared greyed out, preventing any selection. This device was a Chinese variant, originally running ColorOS, that the user had flashed to OxygenOS. While firmware modification can introduce stability risks, protocol failures of this nature often stem from security settings rather than OS corruption.
Investigation revealed that the entire “Select USB Configuration” menu was disabled. Essential protocols, including PTP (Picture Transfer Protocol), USB Tethering, and MIDI, were equally unavailable. Standard hardware troubleshooting—swapping cables, changing ports, and restarting the terminal—failed to restore access. This indicated a software-level restriction blocking the handshake between the mobile device and the PC.
The Technical Resolution: USB Debugging
The solution requires forcing the Android Debug Bridge (ADB) interface to initialize. Enabling USB Debugging often overrides the default charging-only restriction by opening a verified communication channel. This action refreshes the USB configuration menu, restoring user control over file transfer protocols.
Step-by-Step Implementation Guide
Follow these precise steps to restore USB functionality on the OnePlus 15:
Step 1: Activate Developer Options
Navigate to Settings > About Device > Version. Locate the Version Number and tap it seven times consecutively. A system toast message will confirm that “You are now a developer.”
Step 2: Enable USB Debugging
Return to the main menu and select Additional Settings > Developer Options. Locate the toggle for USB Debugging and switch it to “On.”
Step 3: Establish Connection
Connect the OnePlus 15 to your computer using a data-capable USB cable. The device will display a security prompt asking to allow USB debugging; select OK or Allow.
Step 4: Configure USB Protocol
Access the Select USB Configuration menu within Settings. The previously greyed-out options will now be active. Select File Transfer to mount the device storage on your PC.
If you encounter greyed-out USB menus on any Android device running OxygenOS, prioritizing this developer-level override often resolves the handshake failure without requiring a factory reset.