problem on mac os

Hello! I began to edit the map in unity, and then when I finished editing it, I had to keep it. I went into Asessts then pressed the Build level all platforms, and I get the error:

Why is that ?????? what problem????

FileNotFoundException: maps \ diemensland does not exist System.IO.File.Copy (System.String sourceFileName, System.String destFileName, Boolean overwrite) (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/mcs/class/corlib/System.IO/ File.cs: 107) LevelBuilder.BuildMapPlatform (System.String mapName, System.String path, BuildTarget target, System.String shortName) (at Assets / Scripts / Editor / LevelBuilder.cs: 81) LevelBuilder.BuildMap (System.String mapName, System.String path, Boolean windowsOnly) (at Assets / Scripts / Editor / LevelBuilder.cs: 54) LevelBuilder.BuildAllMaps () (at Assets / Scripts / Editor / LevelBuilder.cs: 42)