SOLVED: I have been configuring the supervisor “–limit-request-line 0”, I detail solution:
Added option --limit-request-line 0 into wsgi server startup line.
Config file [/home/erpnext/frappe-bench/config/supervisor.conf]:
line 2> command=/home/erpnext/frappe-bench/env/bin/gunicorn -b 127.0.0.1:8000 -w 2 -t 120 --limit-request-line 0 frappe.app:application
In order to apply changes restart wsgi server:
sudo supervisorctl reload
see the link where you get the solution (@David_Stegnitz)