Quote Originally Posted by Loveboy View Post
LOL? So, how to fix this error?
He explained that here
Open the map with notepad++ or any other programming tool. You will see these lines (for this example I'm going to use Area 51 map, made by .complex Matty)

"The Map" flags expanded
"Brushes" flags expanded
"Brushes/Tools" flags
"Triangles" flags expanded
"Entities" flags expanded
"Entities/Models" flags
"Entities/Spawns" flags
Now, hit Ctrl+F (searching tool), insert these values and hit the "Replace all" button.

Search: layer "Brushes"
Replace with: <leave this box empty>
Do the same for the rest ("Brushes/Tools","Triangles","Entities","Entities/Models","Entities/Spawns"), and after you have replaced all of them, delete the lines at the begginning of the .map (the ones I have quoted).