I have no idea how to fix this, but I'd like to find out too.
For what its worth, when you get to step_3_install_this-v4.2.0_to_v4.3.0 and you're about to import sql_update.sql, edit the file, and take out the following line:
('boot', 'escort_core', '$GLOBALS[''rlEscort''] -> hookBoot();', 'active'),
That will fix the problem.