PICRUSt : Error message when "Normalize By Copy Number"


I am trying to run the first step of PICRUSt from Galaxy /Hutlab (Galaxy) which aims to “Normalize By Copy Number”.

I am using the template file proposed by the website (called sample file) but I am getting this error :

Traceback (most recent call last):
*** File “/galaxy-central/tools/picrust/scripts/normalize_by_copy_number.py”, line 146, in ***
*** main()***
*** File “/galaxy-central/tools/picrust/scripts/normalize_by_copy_number.py”, line 74, in main***
*** raise ValueEr***

Do you know what can I do to fix that ?