I'm getting the following error from Chrome console in odoo 11:

web/image?model=product.template&field=image_small&id=3506&unique=:1 Failed to load resource: net::ERR_HTTP2_PROTOCOL_ERROR

Checking on odoo server log I can find the following error:

Odoo 11.0\python\lib\threading.py", line 846, in start
    _start_new_thread(self._bootstrap, ())
RuntimeError: can't start new thread

the following is my odoo.conf file:

[options]
limit_memory_hard = None
limit_memory_soft = None
limit_request = None
limit_time_cpu = None
limit_time_real = None
limit_time_real_cron = None
list_db = True
log_db = False
log_db_level = warning
log_handler = :INFO
log_level = info
logfile = C:\Program Files (x86)\Odoo 11.0\server\odoo.log
logrotate = False
longpolling_port = 8072
max_cron_threads = 2
osv_memory_age_limit = 1.0
osv_memory_count_limit = False
pg_path = C:\Program Files (x86)\Odoo 11.0\PostgreSQL\bin
pidfile = False
proxy_mode = True
reportgz = False
server_wide_modules = web

syslog = False
test_commit = False
test_enable = False
test_file = False
test_report_directory = False
translate_modules = ['all']
unaccent = False
without_demo = False
workers = None

And this is my server hardware:

any suggestion on the error cause?

thank you,