Thread:Extension talk:Scribunto/Scribunto Script Error

I'm suddenly getting this error on every infobox call on any page.

Lua error in mw.html.lua at line 253: Invalid class given: The name must be either a string or a number.

Backtrace:

(tail call): ? [C]: in function "error" mw.html.lua:253: in function "addClass" Module:Infobox:233: ? (tail call): ? mw.lua:567: ? (tail call): ? [C]: in function "xpcall" MWServer.lua:87: in function "handleCall" MWServer.lua:301: in function "dispatch" MWServer.lua:40: in function "execute" mw_main.lua:7: in main chunk [C]: ?

Can anyone help me out? I'm not super advanced with this sort of stuff.