Ch19 benchmarker:start(SlidingWindow5). variable is unbound

I am try to execute the module in CH19 Forex Trader. When running the following I get a response stating that the * 1: variable 'SlidingWindow5' is unbound. Any help on actually executing this would be appreciated.

c(polis).
polis:sync().
polis:reset().
polis:start().
benchmarker:start(SlidingWindow5).

• 1: variable 'SlidingWindow5' is unbound

I have also tried > benchmarker:start("SlidingWindow5").
Which executes but crashes....

=CRASH REPORT==== 2-May-2020::20:57:43.067000 ===
crasher:
initial call: population_monitor:init/1
pid: <0.432.0>
registered_name: []
exception error: bad argument
in function register/2
called as register(monitor,<0.432.0>)
in call from population_monitor:init/1 (population_monitor.erl, line 81)
in call from gen_server:init_it/2 (gen_server.erl, line 374)
in call from gen_server:init_it/6 (gen_server.erl, line 342)
ancestors: [<0.429.0>]
message_queue_len: 0
messages: []
links: []
dictionary: []
trap_exit: true
status: running
heap_size: 376
stack_size: 27
reductions: 197
neighbours: