Android: IllegalArgumentException: Two views have same id in the hierarchy

Question

I know this error may occur if you use same id for two views. But, in my case, I changed the id of the view 3 times to different names. Searched the project for duplicate id, there is no view with this id. I still get this occur when I open the app. I've rebuild the project also.

Any suggestions?

java.lang.RuntimeException: Unable to start activity 
ComponentInfo{com.myapp.test/com.myapp.test.MainActivity}: java.lang.IllegalArgumentException: Wrong state class, expecting View State but received class android.support.design.stateful.ExtendableSavedState instead. This usually happens when two views of different type have the same id in the same hierarchy. This view's id is id/fab_main_rs. Make sure other views do not use the same id.

Answer 1

I believe that you are missing the + in front of your id definition.

ie. instead of android:id="id/fab_main_rs" you should have android:id="@+id/fab_main_rs"