My good friend, known as playrebot on ROBLOX, found this.
Source of the CoreScript. (Note that line numbers are 2 higher in the ROBLOX asset than in the repository because a header is added.)
Looks fine to me, and nothing nearby has been changed recently, and I can’t reproduce the error message myself.
I’m getting it too, or so I believe. I keep going to games and receiving no PlayerList, this could possibly be the cause. I’ll let you know a bit later if it’s still occurring.
I got this error just by opening a place up in studio, didn’t even have to test server or play solo.
[quote] Source of the CoreScript. (Note that line numbers are 2 higher in the ROBLOX asset than in the repository because a header is added.)
Looks fine to me, and nothing nearby has been changed recently, and I can’t reproduce the error message myself. [/quote]
Those sources are not the ones ROBLOX pulls when requesting them. They are just, there, I guess. 
@Reinitialized, roblox uses the same code, it does not pull from there correct, but it’s the same code.
And i’m getting this problem 50% of the time my self.