Check the experation date on the yeast packet, then, bloom the yeast
in a quarter cup of warm water before you use it. To do this, put a
quarter cup of warm water into a small bowl and stir in the yeast. If
the yeast is good, it will start growing in about 10 minutes. If the
yeast doesn't do anything, you need to get new yeast. Also, was your
bread dough hydrated enough. Wetter is better. If the dough is too
dry, it will not rise properly.