Failed to load AppCompat ActionBar with unknown error?

Question

build.gradle file

    apply plugin: \'com.android.application\'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId \"io.d         


        

Answer 1

This worked for me when that happened, I dont know why it doesn't work with 28:

//use this instead 
compileSdkVersion 27
buildToolsVersion '27.0.3'
targetSdkVersion 27

dependencies{

//switch to these
implementation 'com.android.support:appcompat-v7:27.0.0-alpha'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
implementation 'com.android.support:design:27.0.0'

}