Report creation fails: cannot POST (404)

Hello,

I’m trying out the reporting feature from the free enterprise license, attempting to create a report fails with the following message:

Creating report "test" failed with status: Error: cannot POST http://<public_ip>:9000/api/plugins/org.graylog.plugins.report/reports (404)

No errors or relevant messages in server log. Also there is no proxy or reverse proxy as of yet. Enterprise license seems to be installed as it should have (State - No problems detected).

The widget from which the report is created displays with no visible problems.

Graylog was installed from the debian repo, here’s the list of installed packages with versions:

# dpkg -l | grep graylog                                                                                                                                                                                                                         
ii  graylog-3.3-repository                  1-1                          all          Package to install Graylog 3.3 GPG key and repository                                                                                                                                 
ii  graylog-enterprise-integrations-plugins 3.3.5-1                      all          Graylog Enterprise Integrations plugins
ii  graylog-enterprise-plugins              3.3.5-1                      all          Graylog Enterprise plugins
ii  graylog-integrations-plugins            3.3.5-1                      all          Graylog Integrations plugins
ii  graylog-server                          3.3.5-1                      all          Graylog server

What could be the source of the problem, and where should I start looking?

Thanks in advance.