Django==1.10.2
django-grappelli==2.8.2
django-fsm==2.4.0
django-fsm-admin==1.2.3
django-fsm-log==1.3.0
It appears that the fsm_submit_line_grappelli template is not receiving any context, and therefore fails to build the correct "delete" URL.
I've mentioned this over at sehmaschine/django-grappelli#783 - not sure where the problem lies yet.