This guide will explain the process of how to fix a duplicated or deleted navmesh caused by either a bug in the CK or by accidentally merging two or more navmesh islands.
The CK reports errors similar to this:
The errors will be listed in the EditorWarnings.txt file in your Skyrim folder.
1. You deleted a vanilla navmesh using the cell window in the CK.
2. You accidentally merged two navmeshes the CK listed as islands.
In either case, if the err