Не удалось найти класс 'android.widget.ThemedSpinnerAdapter' [Android Studio]

Я получаю эту странную ошибку, когда пытаюсь запустить приложение на устройстве pre API 21:

I/Choreographer: Skipped 39 frames!  The application may be doing too much work on its main thread.
12-10 07:58:44.179 4469-4472/projects.test.com.webviewtest D/dalvikvm: GC_CONCURRENT freed 156K, 4% free 4561K/4744K, paused 4ms+12ms, total 76ms
12-10 07:58:44.409 4469-4469/projects.test.com.webviewtest I/dalvikvm: Could not find method android.widget.Spinner.getPopupContext, referenced from method android.support.v7.widget.AppCompatSpinner.getPopupContext
12-10 07:58:44.409 4469-4469/projects.test.com.webviewtest W/dalvikvm: VFY: unable to resolve virtual method 18719: Landroid/widget/Spinner;.getPopupContext ()Landroid/content/Context;
12-10 07:58:44.409 4469-4469/projects.test.com.webviewtest D/dalvikvm: VFY: replacing opcode 0x6f at 0x000b
12-10 07:58:44.419 4469-4469/projects.test.com.webviewtest I/dalvikvm: Could not find method android.content.Context.getDrawable, referenced from method android.support.v7.widget.AppCompatSpinner.setPopupBackgroundResource
12-10 07:58:44.419 4469-4469/projects.test.com.webviewtest W/dalvikvm: VFY: unable to resolve virtual method 255: Landroid/content/Context;.getDrawable (I)Landroid/graphics/drawable/Drawable;
12-10 07:58:44.419 4469-4469/projects.test.com.webviewtest D/dalvikvm: VFY: replacing opcode 0x6e at 0x0004
12-10 07:58:44.429 4469-4469/projects.test.com.webviewtest I/dalvikvm: Could not find method android.widget.PopupWindow.showAsDropDown, referenced from method android.support.v7.widget.AppCompatPopupWindow.showAsDropDown
12-10 07:58:44.429 4469-4469/projects.test.com.webviewtest W/dalvikvm: VFY: unable to resolve virtual method 18641: Landroid/widget/PopupWindow;.showAsDropDown (Landroid/view/View;III)V
12-10 07:58:44.429 4469-4469/projects.test.com.webviewtest D/dalvikvm: VFY: replacing opcode 0x6f at 0x000d
12-10 07:58:44.459 4469-4469/projects.test.com.webviewtest I/dalvikvm: Could not find method android.widget.CompoundButton.drawableHotspotChanged, referenced from method android.support.v7.widget.SwitchCompat.drawableHotspotChanged
12-10 07:58:44.459 4469-4469/projects.test.com.webviewtest W/dalvikvm: VFY: unable to resolve virtual method 18333: Landroid/widget/CompoundButton;.drawableHotspotChanged (FF)V
12-10 07:58:44.459 4469-4469/projects.test.com.webviewtest D/dalvikvm: VFY: replacing opcode 0x6f at 0x0006
12-10 07:58:44.559 4469-4469/projects.test.com.webviewtest E/dalvikvm: Could not find class 'android.widget.ThemedSpinnerAdapter', referenced from method android.support.v7.widget.AppCompatSpinner$DropDownAdapter.<init>
12-10 07:58:44.569 4469-4469/projects.test.com.webviewtest W/dalvikvm: VFY: unable to resolve instanceof 2184 (Landroid/widget/ThemedSpinnerAdapter;) in Landroid/support/v7/widget/AppCompatSpinner$DropDownAdapter;
12-10 07:58:44.569 4469-4469/projects.test.com.webviewtest D/dalvikvm: VFY: replacing opcode 0x20 at 0x0016

На самом деле я не получаю ANR или, к сожалению, ваше приложение перестало работать, приложение тихо выходит на главную работу.

Я не использую никаких тяжелых изображений в своем приложении, просто страницу с четырьмя прядильщиками.

В частности, эта строка выделена красным цветом:

E/dalvikvm: Could not find class 'android.widget.ThemedSpinnerAdapter', referenced from method android.support.v7.widget.AppCompatSpinner$DropDownAdapter.<init>

Однако, поскольку я не использую eclipse, я уверен, что у меня есть правильный импорт, используя gradle:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.1"

    defaultConfig {
        applicationId "projects.test.com.webviewtest"
        minSdkVersion 14
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.1.1'
    compile 'com.android.support:design:23.1.1'
    compile 'com.android.support:recyclerview-v7:23.1.1'
}