Sometimes, you may see a situation where a user cannot add a new workitem. This might be when they are looking at a Portfolio Item and want to add a new child backlog item. The Add button is grayed out, for example. If they are in a Story or Defect, the Add button will be there, but the Add Inline will not be....
What the most likely cause of this is that they have a project selected in the main Project Navigator that they do not have rights to add items to, or they have the base container project selected (it would say "All Projects").
Let's say a user is looking at portfolio items in project "My Project". They want to add a child item to that portfolio item but the Add is grayed out.
They don't understand why, because they have rights in My Project. The first thing they need to do is look at the main project navigator.
Notice how it says "All Projects"? That is a placeholder project so that the user can see all the projects at the root level. So, if they have 3 projects at the root level, there would not be a way to see them all to select the one they want without this placeholder.
So, what the user needs to do is click in the project navigator and select "My Project". Then they can add the new item.
The system will try to add any new item to the project selected in the project navigator. Regardless of the project that the portfolio item or whatever belongs to, it will try to add it to the selected project.
Change the project and the Add / Add Inline will be enabled.