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 )