Thread: Website error?

I saw this on page 23 of the Event 2: PeroPero Coliseum but it seems to be in every thread. I don't know what to make of it but it looked important and thought that you should know about it.

Edit: Including this one! Also I'm using chrome atm.

It's just a warning. You only see it right now because I turned on error reporting while working on other stuff.