Note When an Assigned Person Cannot Open the Task
Assigning a task and finding out much later that nobody ever worked on it, because the assigned person could not see it in the first place, no longer goes unnoticed.
You can still assign a task to any person in your account and add further people as collaborators. If one of them has no access to the associated project, however, they cannot open the task. InLoox now points this out directly in the open task: This task is not visible to [First name Last name] due to missing project membership.
The note also resolves the situation right where it appears: you add the person to the project as Team or Managers without leaving the task. They can open it immediately afterwards, and the note disappears.

Help articles: Edit Tasks · Collaborators · Project Members