This started happening a few weeks ago. When i first turn on the phantom, it won't read the sd card. I've tried pulling the card out and reinserting it, won't read it. If turn the phantom on and then immediately turn it off and then back on again, it'll read the sd card. I have no clue what's going on here. It can't be that it needs to warm up, since i can turn it on and then off again within seconds. If it were a bad SD card i would expect it not to work at all, but i have no problems reading or writing to it.

Have you formatted the card in the aircraft using the DJI Go App? What card is it?

Have you tried a different card ?

Hi, I'm sorry to hear that. After saving all your files, please try to manually format the SD card to a computer using a card reader. You can also try to use a different SD card and let me know if the issue is still the same. These are the supported SD cards for your Phantom 4 pro advanced: Micro SD Max Capacity: 128GB Write speed ≥15MB/s, Class 10 or UHS-1 rating required.