I cannot create new dashboard in our JIRA. Doing "Dashboards" -> "Manage Dashboards" -> "Create new dashboard" returns HTTP 404. Other functionality seems to work fine. I didn't find any errors or exceptions in log files (catalina.out and atlassian-jira-sql.log).
In our setup JIRA sits behinds HTTPS proxy. Connector has scheme="https", proxyName, and proxyPort configured, pointing to the proxy (found in other issues these settings can be important). I also double checked permissions on JIRA's home directory, all files belong to JIRA user.