So I had a bit of what I am thinking to be a unique issue. I filmed some drone footage on my new mini 4 pro, and my drone ended up in the water, which meant my SD that was in my drone is not registering on my computer. I also had an "incompatible" SD card in my RC2 controller, which I didn't realize at the time (My first time not using my phone as the remote). I since bought an SD card that was compatible with the remote, and I "migrated" the storage onto the SD card, so when the SD card is in my remote, under "Aircraft album" I see my video clips labeled as "video cache" and I have 0 under saved. I have tried the quick transfer thing and that yielded no results, it only shows you the "saved" album from what I experienced.
So does anyone know how I can move the video cache files to "saved"? I also tried plugging both the remote and the SD card into both a macbook pro and a PC, and I can't find them anywhere. The videos exist somewhere, I am just hoping someone is able to help me find them so I can get them onto a device other than the remote. Anything is better than nothing at this point, I am aware they will likely be less quality.  

Hi, ld123. Thank you for reaching out. Is the "cache when recording" on under settings? If yes, you may unplug the SD from the DJI RC 2, cached video can be read through a card reader or by inserting an SD card into the drone and connecting it to a PC. The file path is Android\data\dji.go.v5\files\MediaCaches. For the drone, were you able to recover it? If not our suggestion is to report a flyaway case via Flyaway Service. After successful registration, a DJI customer service agent will contact you and communicate with the service solution. If ever your drone has been found but is malfunctioning and requires repair, you can submit a repair application via Online Repair Request. Data analysis can also be requested to check what caused the issue (a fee might be applied depending on the warranty). If you need assistance creating a ticket, contact DJI support at (https://www.dji.com/support). Thank you for your continued support.

Hello there,

You need to Open RC2 and locate the video in your cache then Right-click on the video and select Copy Video URL.
Visit an online video downloader site.
Paste the URL and click "Download."
Choose your preferred video quality and download the cached video.

Hope the above will be helpful.

Going in the water should have zero to do with the SD card being read. Cards are almost indestructible. Try cleaning the contacts with an eraser. Without the original files, there is no way to save anything other than the low resolution previews.

Also you can check- Stack over flow