personally I would not use it. because... sorry website wont show up here.. so here is info..
Visual Signs of Spoilage
If a bottle of corn syrup gets hazy or cloudy, this can be a mold haze, and the bottle should not be used. Likewise, if gray mold grows around the opening, it should be discarded.
Neutral Visual Signs
Older bottles of Karo light syrup can develop a yellowish tinge. This is perfectly acceptable and does not affect the flavor of the corn syrup