UnityEngine.UI.dll is in timestamps but is not known in assetdatabase

이 에러가 뜨면 정식이 아늑해 지죠 ㄷㄷ;

포럼에 가서 초반부를 보면 공포에 휩싸일 수 있습니다.(해결 방법이 없;;;;;)

하지만 다행히도 해결되어 있군요

출처 : http://forum.unity3d.com/threads/unityengine-ui-dll-is-in-timestamps-but-is-not-known-in-assetdatabase.274492/

I may have found a workaround. The idea is to totally remove the UI System from Unity then put it back. Unity should reload its modules.

I wrote a full walktrough but overall it is very simple. It is better than a full reimport.

1. Remove the UI System
   1. Close Unity
   2. Access on Unity's installation folder on Explorer or Finder on mac (On mac rightclick on the App and click on ShowPackageContent).
   3. Locate the folder named "UnityExtensions/Unity". (On Mac: "Content/UnityExtensions/Unity".
   4. In this folder you will notice a folder named "GUISystem"
   5. Move this folder from the installation folder (you may need administrator rights). Yes, right. Do not just rename it or move it out the "Unity" folder, Unity will find it... I assure you...
2. Have Unity notice the change
   1. Open Unity again in the project you had the issue
   2. You may have an error "GameObject (named 'Canvas') references runtime script in scene file. Fixing!"
   3. Close Unity, DO NO SAVE ANY SCENE
3. Restore the UI System
1. Make sure Unity is closed
2. Restore the "GUISystem" to its previous location
3. Open Unity again
4. Unity will compile script
5. You will see the warning "Timestamps (19) and assets (21) maps out of sync." and the errors "Asset '' is in assets but has no assettimestamp..." just ignore them
6. Everything should be ok again

간략 해석

1. 유니티를 닫고

2. 유니티가 설치되어 있는 폴더에서 "UnityExtensions/Unity"를 찾습니다.

3. 여기에 "GUISystem" 폴더가 있는데

4. 이 것을 완전하게 (저는 바탕화면에다가 뺏습니다.) 잘라서 외부 폴더에 붙여놓습니다.

1. 다시 유니티를 열고

2. 유니티가 에러가 나거나 그냥 닫힙니다.

3. 만약 유니티가 닫혀있지 않다면
4. 유니트를 종료하고

1. "GUISystem" 폴더를 제자리에 갖다 놓습니다.

2. 그럼 정상적으로 작동될것입니다.