Sushi/nori/yaki paper - out of date?
According to Still Tasty (a site that looks at USDA, CDC and FDA data), nori lasts 2-4 months in the pantry and 4-6 months in the fridge. Also it says: 


  Store in airtight glass or plastic container or in sealed plastic bag. Refrigerate to extend shelf life.


Still, nori is completely dried. I imagine that the concern beyond that time frame is staleness, not safety.

I have nori that's years old. I would check to be sure that it is somewhat brittle, not leather-like before I used it, but for quality, not safety.