If it wasn't stored in the ref after opening, check for molds. Had a bottle of Oyster Sauce thrown because of this. :\
:whiste:
It was refrigerated, and I don't see any mold.
Then you are looking at a flavor issue. How does it taste?
My rule of thumb concerning food safety is if you are asking a question about food, don't eat it and throw it away. It does not make sense to gamble with food safety.