When a Task/Milestone is deleted then this Error Message is thrown "PRJ-07581: One or more tasks can not be deleted. This may be due to committed assignment actuals or transactions."
To stop the Hours on this Task/Milestone we can uncheck the "Time Entry".
Can't we delete the task which has actuals posted ?
You can not delete tasks with posted actuals (this is exactly what the message is telling you).
No, we cannot delete the task which has actuals posted.