My chicken smells a bit strange
When you open your vacuum-packed chicken, there can be a strong smell from the packaging simply because the chicken breasts are packed together in such large quantities and the products have been contained. It's also due to the process we use to remove the oxygen from the packaging as we vac-pack to keep the product fresh. This is usually quite a strong smell, but it's because we don't add salt, water or preservatives to our chicken, like some places do.
We'd always advise leaving the meat for 5-15 mins once opened to allow oxygen to get to the meat, and by then the smell should not be noticeable.