Error : Ambiguous method call. Both findViewById (int) in AppCompactActivity and Activity

Question

I am getting the error: \"Ambiguous method call\" on initializing Toolbar using Android Studio 3.0 RC1. I have extended my Activity with AppCompatActivity and compiling my appli

Answer 1

This can suddenly appear when running a code analyzer like FindBugs-IDEA. A quick way to clear the warning is to temporarily change the buildToolsVersion in your app/build.gradle then change it back again.

For example, follow these steps:

1. Open your app/build.gradle file.
2. Change buildToolsVersion to '26.0.1' then sync project (press the 'Sync Now' button when it appears at the top)
3. Change the buildToolsVersion back to whatever you had before.
4. Press the 'Sync Now' button

This should clear the error.