A surgical instrument comprises a body, shaft, and end effector. The shaft couples the end effector and body together. The end effector comprises an anvil and lower jaw configured to receive a surgical staple cartridge. The anvil is configured to pivot toward and away from the staple cartridge and lower jaw. The shaft assembly comprises a knife member configured to longitudinally translate to thereby substantially simultaneously cut clamped tissue and staple the severed tissue. The end effector may comprise lockout features configure to prevent longitudinal translation of the knife member. The end effector or staple cartridge may comprise lockout bypass features configured to prevent lockout of the knife member.
