Root what notification is this?

[defTwitch]

To left of airplane mode notification is a little icon that looks like an SD card with an exclamation point. SD card seems fine. I have tons of free space on internal memory and card. Reboot. Clear caches. Fix permissions. Clear all on pull down does not remove... aka it seems to be doing nothing but curious and would like to know what it us and how to remove.

 

[WormDoes]

It's saying there's something wrong with your SD. Possibly not mounted, or didn't mount correctly? I would take it out, make a backup on PC (just in case) and then put it back in and see if it goes away