I got a Dji Spark drone for my birthday last week. I was so happy. Then over the last week I have tried to something remarkable: get the drone to take off.
I'm not alone:

I received my DJI Spark today after waiting eagerly for 2 weeks for it to arrive and I've just spent the whole day trying to get it to fly and so far no joy. I've stumbled upon what appears to be some sort of bug as I have done everything that is stated on the manuals and on all guides that I've seen for the DJI Spark. After setting everything up and getting everything updated I was ready to take off with all systems and camera operational when I see this red bar up top saying CANNOT TAKE OFF and then I click on it and it takes me to STATUS which says I have the latest firmware and when I click on that I see AIRCRAFT IS LOCKED. I have tried searching on google for a fix for this but all the fixes I see I have tried and nothing works.

The solution for Android users:
- Delete the current version of the app. It's your core problem. Many of the 1-star reviews (mine included) were victims of April 25th software release.
- Go to https://www.apkmirror.com/apk/dji-technology-co-ltd/dji-go-4/dji-go-4-4-...
- Download the Feb. release (it's the one I used).
- Install it (Android will try to warn you off of using an APK)
- DO NOT do firmware releases or other updates. The post-April code looks to be all bad.

I tried this today and I was flying inside of 15 minutes.