The Blue Box of Doom in the lower left. Don't panic.
The Blue Box of Doom sometimes appears in the lower left corner of the screen in Foldit.
Despite its ominous name, the Blue Box of Doom is completely harmless. Reports of it being linked to plagues of locusts are mainly anecdotal.
The exact cause of the Blue Box of Doom is not known. It's believed that the BBoD represents a "click map" of the protein, used in processing mouse clicks. The hypothetical click map may reside in video memory, but is normally invisible. It only appears as the Blue Box of Doom once in a great while, coincidentally on the eve of major natural disasters.
Restart Foldit to clear the Blue Box of Doom. Alternately, uninstall Foldit, format your hard drive, disassemble the hard drive and melt the platters in a blast furnace, then throw the rest of the computer in the blast furnace just to be on the safe side. Your cell phone, too. Immediately leave home with only the clothes on your back. Have no further contact with your friends and family. Hop the nearest freight train to an unknown destination.
Tip: wear earplugs. Those metal box cars are really noisy. It's not like the old days!
Once you reach a port city, disguise yourself as an able-bodied seaman and talk your way on board a tramp steamer bound to nowhere.
Tip: earplugs again. Tramp steamers these days are really diesel, and those engines get pretty loud. Again, things were better in the old days.
Lose yourself in the most remote corners of the globe for 7, 14, or 21 years. Go for 77 if you have the time.
While these precautions may seem extreme, you can't be too careful when dealing with the Blue Box of Doom. LFB is watching.