Opening a .ai file on Adobe Illustrator on iPad Pro

Hello, users! 

I have just subscribed for Adobe Illustrator on iPad Pro, needing it for work, but I have a tedious problem.

When I try to open a .ai file I airdropped from my Mac to my iPad, Illustrator (on iPad) gives me an error: "Can't open xx.ai file". 
I have checked the file on my Mac and it perfectly opens on Illustrator. I have also tried uploading the file directly from Google Drive (so Mac -> Drive -> iPad), but it doesn't work too.

Any advice on how to solve this problem, please?
Thank you so much!