To reproduce:

1. Download attached project "LightingDataAssetBugRepro.zip" and open in Unity
2. Open "23_LightingRepro" scene
3. Build project with "23_LightingRepro" scene loaded (and active), and "23_LightingRepro_Additive" scene loaded second

Expected Result: UnityEditor should successfully build project
Actual Result: Unity Editor fails to build the project and spams errors to Console:

"Failed to copy '92/923957515e64183d158b1fd86a896806.pos' to 'Temp/StagingArea/Data/GI/level1/92/923957515e64183d158b1fd86a896806.pos'.
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)"

"Build completed with a result of 'Failed'
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)"

"UnityEditor.BuildPlayerWindow+BuildMethodException: 3 errors
at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (BuildPlayerOptions options) [0x00207] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:172
at UnityEditor.BuildPlayerWindow.CallBuildMethods (Boolean askForBuildLocation, BuildOptions defaultBuildOptions) [0x00050] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:83
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)"

Notes:
- This issue appears on Windows and OSX
- Workaround: The problem can be solved by rebaking locally before building but this is a very time-consuming solution
- The user also gets more errors:

"Failed opening GI file at relative path: 'ef/ef081166634c745b7aa529801928f515.rpc.sse'. Absolute path: 'C:/Users/george.rowe/AppData/LocalLow/Unity/Caches/GiCache/ef/ef081166634c745b7aa529801928f515.rpc.sse'."

"Assertion failed: Failed loading Enlighten probe set data for hash: 0xef081166634c745b7aa529801928f515'"

- Workaround for above errors: Clear the GICache, bake the lights and then build

Reproduced on Unity 2017.2.0p2, 2017.2.1p2, 2017.3.0p3 and 2018.1.0b4
Not reproduced on Unity 2017.2.0p1 and 2017.1.3f1
Regression on Unity 2017.2.0p2