Hi Atlassian Team and everyone else!
Once you make a severe mistake editing announcement banner's code and no pages are rendered, then the solution is to delete the banner trough database and then restart Jira.
This can be very time consumption and when the mistake is done on production environment it's very annoying.
Maybe it would be a good idea not show the announcement banner at Announcement Banner's editing page, so you always would have the opportunity to easily fix errors.
What do you think about this?