I recently purchased several new 200 GB cards.... SanDisk Ultra, microSDXC UHS-I Card, Premium Edition, Class 10, 200 GB.
I've tried these cards in both my Inspire 1 and my Osmo. Both devices display "Reformat Recommended" no matter how many times I format them bith in the devices or on the computer.
Today I was using one in my Inspire; and it does record fine, to it even while displaying "reformat recommended" message, but it did tell me card was full at one point. after viewing the card on my computer... only 35.4 GB were used, with 147 GB still free.

What is the MAX SIZE cards the Inspire or Osmo are compatable with. I was hoping the 200GB would work and give me lots of room for 4K.

Max size is 64GB

http://www.dji.com/inspire-1/info#specs

Supported SD Card Types        Micro SD
Max capacity: 64 GB. Class 10 or UHS-1 rating required.

I was going to say a 200gb card is way to big lol. but ya the max is 64GB