I don't know if this helps but I was having all sorts of problems loading the latest firmware, 1.5.0.30, into our I1. I reinstalled 1.1.0.40 and it told me the craft needed an update. So, I tried 1.5.0.30 again and it worked. Here's the weird part, the I1 made all the right noises as it updated, lights flashed and the gimbal spun around but when I checked the txt message after upgrading it said, "error: corrupted firmware file, reload from dji website and try again." When I checked what the firmware was on the GoApp it confirmed the upgrade and when I sent DJI my log file they confirmed it had updated.
So, maybe try reloading the last upgrade, then try 1.5.0.30 again, with fresh batteries! Good Luck.