Well - after a full day of hiking and getting shots here and there my Mini 2 says there is no SD card, when there is one inserted.   When I put the card my my Win 10 laptop it says there is no recognizable file system on it.   My iPhone also will not see the card.

While I can reformat the card, is there anyway to recover anything from it?  Or is it just a loss?

It sounds like you might have shut down the aircraft without stopping recording? Try putting the card back in the aircraft and take a photo.

Check disk fixed the issue and I was able to recover all the days video.   

Thank goodness.

Hi there. We're glad that you already manage to fix the issue that you had experience and recover the said files. Please don't hesitate to reach us if you have other inquiries or concerns. Thank you!

Frank Alonso Posted at 7-17 15:31
Check disk fixed the issue and I was able to recover all the days video.   

Thank goodness.

Great.  Glad you were able to recover all the footage.  

I am guessing it's a SanDisk.  I know a lot of people swear by SanDisk.  And I may get a lot of flack for this.  But as a former Photographer, and now drone pilot who relies on quality, SanDisk has gone WAY down hill in the last few years.  A life time warranty means nothing, when your files are lost and unrecoverable.  I used to swear by SanDisk and used them exclusively in all my D-SLRs, now, never again.  I won't even use a SanDisk in my IP Cameras.  They have failed me way too often.  I have switched to Samsung, I find them VERY reliable, fast and affordable.  
I know you got your files back and I am glad, and this may not have been a SANDISK issue, but I strongly suggest if you are using SanDisk.
One more thing, many don't know.  SD Cards have a "Write Limit" aka limited write cycles, I find with SanDisk they are WELL below what they report for the write cycle max on their Secure Digital cards.