It looks like lua_tointegerx previously handled floating point numbers differently. Now it seems to return 0 when passed a floating point number.

I changed this on my end by using lua_tonumber rather than lua_tointeger in the (one) place I've seen the issue so far on Stitch (AddSpellBonus), but I'm not sure if there's other issues that were caused by the change.

Just a heads up.

that would make sense since integer should not handle floatingpoint anyways should it

Probably, it had just worked differently (probably in an undocumented/unintended way) previously, and now they changed it in Lua 5.3 (?).