Weird error pops up sometimes

"K:/ server extension failed"

Thats the weird error message I get sometimes. Nothing seems to be wrong or not working, so I don't know what it is.

The only thing plugged in to the K drive is a small external hard drive that I've been putting some videos on. But they are all there, they all play, and nothing seems wrong with any of it.

So, does anybody know what this error is? What does it mean?

 

Google found things about 'server execution failed' but not 'server extension failed'. You sure you got that error message right ?

 

Sorry, I get 'dyslexic' when I'm tired.

Here is a screenshot....