addContentView dosn't show/apper in Unity 5.6.0

Game webview content for android webview code for addContentView dosn't apper, but setContentView only apper in unity 5.6.0f3, but addContentView is working well in unity 5.5.0f3. Please give me the solution for this problem or solve this problem in unity 5.6.0 version as soon as possible.