I wonder if the if the venison was freezer burned. Over two years, especially if the meat was stored in a frost free freezer, is a long time.
The age of the spices might also be a factor. The rule of thumb that I have heard is that after about two years, spices lose quite a bit of their flavor. Oh course, spices subjected to heat will degrade faster. And the storage container makes a difference. Glass with a metal cap would be the best and a light plastic bag with a twist tie would be the poorest.
If you were unlucky enough to have both freezer burned meat, and old spices, they could be the source of your problems.