Comment 14 for bug 50198

If you use a laptop, and close the screen, and require a password to be entered to return to the desktop, the text box sometimes shows with this message. it then closes and a fresh dialog shows.

Presumably the dialog was triggered before sleep and it has a lifespan set which will be expired when when you return to the laptop later.

It wastes about 5 seconds every time you open your laptop - so whilst the bug might be minor in that it doesn't affect functionality, I am tired of seeing it, and I suspect I am a fairly forgiving user.