Failed to load AppCompat ActionBar with unknown error in android studio 3.1.4

Question

I am getting this error in android studio

Render problem

Failed to load AppCompat ActionBar with unknown error.

Failed to instantia

Answer 1

As Dona said. But no need to change the gradel, Just change the styles xml-file from:

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

to this:

<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">

Don't know why, but it work

Answer 2

com.android.support:appcompat-v7:28.0.0-alpha3 has few bugs

change

implementation 'com.android.support:appcompat-v7:28.0.0-alpha3'

to

implementation 'com.android.support:appcompat-v7:28.0.0-alpha1'

or In your styles xml-file change this:

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

to this:

<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">

it will work

Answer 3

Usuallly it solves with the correction of the following code:

com.android.support:appcompat-v7:28.0.0-alpha3

to

com.android.support:appcompat-v7:28.0.0-alpha1

but for other persons (like me) is not the case, so what else? there's a problem with the theme of the app that makes some kind of error at the moment of previsualization. To fix that, I've made this: (Image)

https://yadi.sk/i/QCM_pCvvAcajOw

Changing the theme of the document everything got solved.