Ndtyjky

I needed to check out an old project which required me to download build-tools version 23.0.0 for some codes and i loaded it in my updated android studio.

Now the layout files doesn't show any preview for me on any working project which i designed without any issues or on a new project before loading that old project
here are the errors i get while starting a new project:

NOTE: One or more layouts are missing the layout_width or layout_height attributes. These are required in most layouts.

And

The following classes could not be found:

- ProjectState (Fix Build Path, Edit XML)
- component (Fix Build Path, Edit XML)
- config (Fix Build Path, Edit XML)
- configuration (Fix Build Path, Edit XML)
- configurations (Fix Build Path, Edit XML)
- device (Fix Build Path, Edit XML)
- entry (Fix Build Path, Edit XML)
- expand (Fix Build Path, Edit XML)
- file (Fix Build Path, Edit XML)
- item (Fix Build Path, Edit XML)
- leaf (Fix Build Path, Edit XML)
- list (Fix Build Path, Edit XML)
- option (Fix Build Path, Edit XML)
- path (Fix Build Path, Edit XML)
- project (Fix Build Path, Edit XML)
- projectState (Fix Build Path, Edit XML)
- projects_view (Fix Build Path, Edit XML)
- select (Fix Build Path, Edit XML)
- shared (Fix Build Path, Edit XML)
- state (Fix Build Path, Edit XML)
- system (Fix Build Path, Edit XML)
- tree_state (Fix Build Path, Edit XML)
Tip: Try to build the project. Tip: Try to refresh the layout.

And

Render Problem: Failed to load AppCompat ActionBar with unknown error

And

Failed to instantiate one or more classes

The following classes could not be instantiated:
- android.support.v7.app.WindowDecorActionBar (Open Class, Show Exception, Clear Cache)
Tip: Use View.isInEditMode() in your custom views to skip code or show sample data when shown in the IDE. If this is an unexpected error you can also try to build the project, then manually refresh the layout.

Image shows MainActivity as Unresolved class in tool:context=".MainActivity"

Methods i tried to resolve this issue:

1. Invalidate cache and restart


2. Clean and Rebuild project


3. Change sdk version from 28.0.0 to 27.1.1 (I've been working on a project with sdk 28.0.0 earlier without any issue before loading that
   old project)


4. Reinstalled entire android studio, deleting caches except sdk


5. Force refresh layout


6. Set build-tools version in settings to 28.0.3

build.gradle(Module: app):

apply plugin: 'com.android.application'



android {

    compileSdkVersion 28

    defaultConfig {

        applicationId "<Name Removed>"

    minSdkVersion 28

    targetSdkVersion 28

    versionCode 1

    versionName "1.0"

       testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

}

buildTypes {

    release {

        minifyEnabled false

        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

    }

}

buildToolsVersion '28.0.3'

}



dependencies {

    implementation fileTree(include: ['*.jar'], dir: 'libs')

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

    implementation 'com.android.support.constraint:constraint-layout:1.1.3'

    testImplementation 'junit:junit:4.12'

    androidTestImplementation 'com.android.support.test:runner:1.0.2'

    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

}

build.gradle(project:project-name)

buildscript {



    repositories {

        google()

        jcenter()

    }

    dependencies {

        classpath 'com.android.tools.build:gradle:3.2.1'





        // NOTE: Do not place your application dependencies here; they belong

        // in the individual module build.gradle files

}

}



allprojects {

    repositories {

        google()

        jcenter()

    }

}



task clean(type: Delete) {

    delete rootProject.buildDir

}

merged manifest

Manifest Sources 



app main manifest (this file)

 Other Manifest Files (Included in merge, but did     not contribute any elements) animated-vector-    drawable:28.0.0 manifest, appcompat-v7:28.0.0 manifest,     support:asynclayoutinflater:28.0.0 manifest,     constraint-layout:1.1.3 manifest,     support:coordinatorlayout:28.0.0 manifest,     support:cursoradapter:28.0.0 manifest,     support:customview:28.0.0 manifest,     support:documentfile:28.0.0 manifest,     support:drawerlayout:28.0.0 manifest,     support:interpolator:28.0.0 manifest,     lifecycle:livedata:1.1.1 manifest, livedata-core:1.1.1     manifest, support:loader:28.0.0 manifest,     support:localbroadcastmanager:28.0.0 manifest,     support:print:28.0.0 manifest, core:runtime:1.1.1     manifest, lifecycle:runtime:1.1.1 manifest,     support:slidingpanelayout:28.0.0 manifest, support-    compat:28.0.0 manifest, support-core-ui:28.0.0     manifest, support-core-utils:28.0.0 manifest, support-    fragment:28.0.0 manifest, support-vector-    drawable:28.0.0 manifest,     support:swiperefreshlayout:28.0.0 manifest,     support:versionedparcelable:28.0.0 manifest,     lifecycle:viewmodel:1.1.1 manifest,         support:viewpager:28.0.0 manifest 

I encountered something similar with Android Studio 3.2.1. The project built successfully, no issues, but nothing is displayed on my layout preview view. Tried clean/rebuild, invalidate cache/restart, close/open project, force refresh layout, sync project with gradle files. The only thing that helped me and restored my layout Design preview was to delete caches folder in .AndroidStudio3.2system.

Ok so i found the solution. For anyone who face this issue,

Go to sdk folder, open build tools and delete them all..
Open Android studio and let them redownload.