On which system is your computer running?
If it is Windows 8, there is a problem with DJI drivers and Win.
Google ""how to remove driver signature on Windows 8"
That helped me
If the Assistant 2 isn't opening at all or recognizing the I2 when plugged into Windows 10-64, it's likely your drivers are not communicating well, or a bad USB cable (I got a bunch of bum cables and don't know if they are super fragile or what.). Above someone mentioned a way to get the drivers to install properly as DJI (I think?) isn't using signed drivers by Microsoft so it might be a security issue to block their install.
I also had issues with Assistant 2 version 1.2.2 that I got off their Mavic Air page and had to go back to version 1.2.0 with the I2 and it worked for me. DJI software is cantankerous, imho.