I have two error messages popping up when previewing my mission in 3D editor.
The first is when a task is assigned for the first time after starting the mission.
First task assigned

The second is on exiting the mission and returning to the editor.
Quitting mission

Neither have made the mission unplayable as far as I can tell. However I would like to fix them before completing my mission making.

The tasking error creates a significant pause when it appears. Mission seems to run OK but the pausing on task creation is significant.