Complex sentence: Hasenjaeger was presented with a 100 character encrypted message for analysis and found a weakness which enabled the identification of the correct wiring rotors and also the appropriate rotor positions, to decrypt the messages.
Split into simpler sentences: Hasenjaeger was presented with a 100 character encrypted message for analysis. He subsequently found a weakness which enabled the identification of the correct wiring rotors, and also the appropriate rotor positions, which enabled him to successfully decrypt the messages.