Could not find class 'dalvik.system....'

I am running one android application in version 4.4.4 After load application i can't tap any button and in logcat this is an error:

 E/dalvikvm: Could not find class 'dalvik.system.DelegateLastClassLoader', referenced from method ab.b 

This is my gradle file:

 apply plugin: 'com.android.application' android { compileSdkVersion 28 defaultConfig { applicationId "com.app.name" minSdkVersion 14 targetSdkVersion 28 versionCode 105 versionName "1.0.5" testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' } } lintOptions { checkReleaseBuilds false } } dependencies { implementation fileTree(dir: 'libs', include: ['*.jar']) 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' implementation 'com.google.android.gms:play-services-ads:17.1.2' } 

In higher android versions everything works fine. Help please )