From time to time it is necessary to use confirm layout. Some examples of when you need to run this feature are, if you get an error when opening your layout that states the your Cad Buffer Is Damaged, or in newer versions of the program you will see a message that you have a Layout Cad corruption or Cad Buffer detection.
In these cases you will need to try and run the Confirm layout tool Located under the Layout tab then look towards the bottom where you will see the confirm layout button.
The Confirm Layout command allows you to retrieve most of the critical components of your layout should the file ever get corrupted. While its use is not often required, this utility command can recover the Walls, Planes, Ridges, Trusses, and Truss Labels from a corrupted layout. When you run the Confirm Layout command, if there is corrupted data in a particular truss, the program will highlight the truss and indicate that this truss is corrupt and will be deleted.
As with all software packages, it is good practice to save your work as you go and at different stages. You may want to save the layout when you finish the walls, perhaps naming the file WALLS.LAY, and then save it again after you've finished the planes, calling it PLANES.LAY, and so on. Also, using the Quick Save (Hot Key Save - F2 function key) and Quick Load (F4 function key reloads Quick Saved file) commands to save your work, as well as the Autosave Minutes feature to automatically save your work at timed intervals, will help minimize the chances of having to start over from scratch. You may need to save your dimensions and labels as confirm layout sometimes will delete these.