Thank you so much ^:)^ ryman01 ^:)^ for your description.
Some users after your comment seemed not recognized it:
Folks:
1. Go to "Files" icon on Airdroid desktop
2. Open the "System" foder (discard the warning)
3. Look out for "mnt" folder
4. Open "mnt" folder and within should be a folder named after your external sd card, open the folder and you can access all files within your external SD
5. After proceeding so, Airdroid recognized my external sd and at the next new connection to my device it offers me under the files window the folders SD card , External SD , System
6. So after going through step 1-4 you have direkt access via file icon B-)