This flashable zip will update or downgrade your Firmware and Modem Files of your OnePlus 3 or 3T.
If you encounter any errors during the installation process, feel free to report it to me.
Normally I test all the .zip files before I upload them, so everything should work fine.
Current stable firmware version: OP3T: 9.0.6 | OP3: 9.0.6
Note: You will lose your data if you are coming from 5.0.x firmware and your storage is encrypted! If you want to upgrade from 5.0.x to 9.0.x firmware and update the ROM and don't want to clean flash, you can follow this guide in order to keep your data (only applies if your data is encrypted) (thanks to @nvertigo67):
[GUIDE][MODDED FIRMWARE][9.0.6][OP3/T]The least annoying 9.0.x firmware