If you accidentally delete a task, you'll need to recreate it from scratch. Open “Active Directory Administrative Centre”.
In this article, we will show you how to quickly clear all offline items in a specified folder as well as recover deleted offline items or undo clearing in Microsoft Outlook. Normally, deleted items are sent to the “Deleted Items” folder (typical of the ‘Recycle Bin’ in Windows). Select the file that you want to restore by clicking the circle next to it, then choose the “Restore” button. To recover a calendar item, right-click on it and then click Move to Calendar. To recover a task, right-click on it and then click Move to Tasks. Click on Search for lost data to begin the search.
I wish you could see a history of the traffic that has been done in Planning so that way you could maybe recover what was deleted. Microsoft to do recover deleted tasks This tracking is so painful to lose.
