Can't add a project and/or context to a task
 

Some how I created a task that I can't add a project and context. In the inspector, the project and context drop-downs are greyed out and unselectable.

How so I fix this?

Which mode are you in? Planning mode? If so, it sounds like the row in question may be a folder.

Folders are used for organizing your projects into related groups, but they aren't actionable, so they don't support project/context assignments...