Applies to: All Reolink cameras that support SD card 

If you tried to capture the live stream picture or capture the video manually with live stream,

Then got the "SD Card is Unavailable" with your Android app, that would your Android phone doesn't allow the reolink app to access the storage.

Please go to Menu->Settings -> Reolink info to allow "Read/ Write /Delete External Storage" permission for the Reolink app since the phone's App Storage Permission was disabled by default.
Read/Write/Delete External Storage Permission

allow read/write permission