This tool can be used to revive a bricked OP6T and remove the ‘Device is corrupt’ error message on boot. Contains the latest MsmDownloadTool v4.0.58 and OOS v9.0.11 and is not compatible with T-mobile models. Might not be latest OOS but it still should help you out of a SoftBrick in any case 😉
~ For Global/McLaren OnePlus 6t Models ~
1. Make sure that your phone is switched off.
2. Open device manager on your Windows PC.
3. Press and hold the Volume Up & Volume Down buttons then connect to your PC using your data cable.
4. Once the device is connected to your Windows PC, check if the phone is being recognized (Other > QUSB_BULK or Ports > Qualcomm).
5. If showing as Other > QUSB_BULK either wait for Windows to install the Qualcomm driver or download the driver below and install.
6. Run MsmDownloadTool V4.0_factory.exe and click Start.
NOTE: This will completely wipe your device and re-lock your bootloader.