It's important to remove unused vertices, line edges, polygons (faces), and parameters. This could be the very cause of the "null" value that MCX is referring to and removing it.
For exemple all of these edges can be removed right?
I can give you the file in PM. Yeah right, blender has closed suddenly.The Crash is abnormal. I can't explain the reason "why" it's crashing unless I see it for myself. It might be necessary for you to send the blend file to me to determine the cause, but that is up to you. When you say that it crashes, are you saying that it closes Blender and goes back to the desktop?
Ok I did the "Cleanup" in edit mode but when I switch in object mode to do the second one I have only 3 options and 1 I can use. Do you have a solution?The proper order to "Cleanup" and reset the "Transforms" is: 1st is the "Transforms" and then the "Cleanups". There are 2 "Cleanups": first is in "Edit" mode and then the "Cleanup" that you showed (2nd picture below). Make sure to select ALL before performing each of the "Cleanups". In the 2nd "Cleanup", you only need to use the first and third that are listed, for now (see pictures):
To reset the rotation and the scale, I have to change it here right?The "Scale": resets it back to 1.0 on all axis whatever unit you are using (metrics or imperial - if you scaled anything or not). Last is the Rotation, resets it back to 0 (whether you rotated anything or not.)
The scenery is for P3D v4.5 and higher and for MSFS.BTW, what Flight Sim is this terminal for?