Meitner's discovery - that the electrons produced when neutrons decay into protons don't have a single specific energy but rather a range of energies - led to a crisis in nuclear physics around 1929.
Bohr decided that the only way out was a failure of conservation of energy! Maybe it was only conserved on average. Pauli thought of a slightly less radical way out: maybe some of the energy is carried off by yet another neutral particle, this time one of low mass.
Two mysterious unseen neutral particles was a lot to stomach! In 1931 Fermi called the big one the "neutron" and the little one the "neutrino". In 1932 Chadwick realized that you could create beams of neutrons by hitting beryllium with α particles. The neutrino was only seen much later, in the 1950s.
(I hope people remember this story when they scoff at the notion that "dark matter" makes up most of the universe: even if something is hard to see, it might still exist.)
Back to Meitner:
When Hitler gained power over Germany in 1933, her life became increasingly tough, especially because she was a Jew. In May of that year, Nazi students at her university set fire to books by undesirable writers such as Mann, Kafka, and Einstein.
By September, Meitner received a letter saying she was dismissed from her professorship. Nonetheless, she continued to do research.
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