When a bug report is rejected as "invalid", a part of the message indicates that the submitter should "Please follow our submission template and guidelines". This is vague. If the message is going to reference the document, it should provide the document or at least a valid link to it. If Maniphest were to pre-populate a bug report at the time of creation it would further improve communication.
I've had a look at what's going on here:
- If you create a task via Maniphest (i.e. via the '+' in the top-right corner -> Create Task) the description box is left empty (since the task could be for anything). That page is simply titled "Create Task"
- If you create the task via the "Report Bug" button on the homepage, you'll instead see a page title "BF Blender Bug Report", complete with instructions on what to include in the bug report, as well as a pre-populated description box with a basic template.
I think it was expected that most people would just click the "Report Bug" button rather than using the "Create Task" provided natively by Maniphest. I'll let the web-team decide what to do here :)
Ah, yes. On one of my visits I navigated from http://archive.blender.org/development/report-a-bug/ via the link on Blender Bug Tracker which in turn took me to https://developer.blender.org/maniphest/ which is why I have that experience. I got to the same page via a google search for Blender bug template for which the 2nd most common hit was https://developer.blender.org/maniphest/project/2/type/Bug/ , so I believe there are multiple paths to a less than ideal interface.