I found thay you can't record to the onboard sd card on the goggles, so I loaded some stills and movie files from the mavic pro onto the card.  Inserted it, booted up th goggles and all I get is " failed to play file" notice.
????

Hi, thanks for the inquiry. After connecting the aircraft with the DJI Goggles, select “Playback” on the DJI Goggles and choose the images or videos you want to view on the SD card in the aircraft. After opening an image or video, swipe up or down on the touch panel and the system will show the delete and download options. Select “Download” and the image or video will be downloaded to the SD card in the DJI Goggles. There is no image or video will be cached on the SD card in the DJI Goggles. Please keep us posted on the latest progress.

DJI Tony Posted at 2018-12-21 16:47
Hi, thanks for the inquiry. After connecting the aircraft with the DJI Goggles, select “Playback” on the DJI Goggles and choose the images or videos you want to view on the SD card in the aircraft. After opening an image or video, swipe up or down on the touch panel and the system will show the delete and download options. Select “Download” and the image or video will be downloaded to the SD card in the DJI Goggles. There is no image or video will be cached on the SD card in the DJI Goggles. Please keep us posted on the latest progress.

2years after the original post, i still unable to find any solution for this.
I have downloaded the drone's footage into the goggles, and here it is look like....
While other mp4 movie video i put into the goggle's sdcard work just fine...
But why 1080p footage from my mavic2zoom not??

White Goggles
FW 1.04.0500 (latest)