[Miscellaneous Android Development] sToRm1nG:
Something else which is still present:

04-16 16:09:44.428 731 1575 I ActivityManager: Start proc 3590:com.cyngn.theme.chooser/u0a21 for activity com.cyngn.theme.chooser/.ChooserActivity
04-16 16:09:44.469 3590 3590 W System : ClassLoader referenced unknown path: /system/priv-app/ThemeChooser/lib/arm
04-16 16:09:44.501 3590 3590 E MediaPlayer-JNI: JNIMediaPlayerFactory: bIsQCMediaPlayerPresent 0
04-16 16:09:44.501 3590 3590 E MediaPlayer-JNI: JNIMediaPlayerFactory: bIsQCMediaPlayerPresent 0
04-16 16:09:44.505 3590 3590 W art : Before Android 4.1, method void android.widget.ComponentSelectorLinearLayout.drawVerticalDivider(android.graphics.Canvas, int) would have incorrectly overridden the package-private method in android.widget.LinearLayout
04-16 16:09:44.688 3590 3590 I art : Rejecting re-init on previously-failed class java.lang.Class<com.cyngn.theme.chooser.e>
04-16 16:09:44.689 3590 3590 I art : Rejecting re-init on previously-failed class java.lang.Class<com.cyngn.theme.chooser.e>
04-16 16:09:44.690 3590 3590 I art : Rejecting re-init on previously-failed class java.lang.Class<com.cyngn.theme.chooser.e>
04-16 16:09:44.690 3590 3590 I art : Rejecting re-init on previously-failed class java.lang.Class<com.cyngn.theme.chooser.o>
04-16 16:09:44.691 3590 3590 I art : Rejecting re-init on previously-failed class java.lang.Class<com.cyngn.theme.chooser.o>
04-16 16:09:44.691 3590 3590 I art : Rejecting re-init on previously-failed class java.lang.Class<com.cyngn.theme.chooser.e>
04-16 16:09:44.701 3590 3603 E AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
04-16 16:09:44.701 3590 3603 E AndroidRuntime: Process: com.cyngn.theme.chooser, PID: 3590
04-16 16:09:44.701 3590 3603 E AndroidRuntime: Theme: themes:{}
04-16 16:09:44.701 3590 3603 E AndroidRuntime: java.lang.RuntimeException: An error occurred while executing doInBackground()
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at android.os.AsyncTask$3.done(AsyncTask.java:309)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.util.concurrent.FutureTask.run(FutureTask.java:242)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.lang.Thread.run(Thread.java:818)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: Caused by: java.lang.NoClassDefFoundError: Failed resolution of: Landroid/provider/ThemesContract$ThemesColumns;
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at com.cyngn.theme.chooser.b.doInBackground()
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at android.os.AsyncTask$2.call(AsyncTask.java:295)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: ... 4 more
04-16 16:09:44.701 3590 3603 E AndroidRuntime: Caused by: java.lang.ClassNotFoundException: Didn't find class "android.provider.ThemesContract$ThemesColumns" on path: DexPathList[[zip file "/system/priv-app/ThemeChooser/ThemeChooser.apk"],nativeLibraryDirectories=[/system/priv-app/ThemeChooser/lib/arm, /vendor/lib, /system/lib]]
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: ... 7 more
04-16 16:09:44.701 3590 3603 E AndroidRuntime: Suppressed: java.lang.ClassNotFoundException: android.provider.ThemesContract$ThemesColumns
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.lang.Class.classForName(Native Method)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
04-16 16:09:44.701 3590 3603 E AndroidRuntime: ... 8 more
04-16 16:09:44.701 3590 3603 E AndroidRuntime: Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available
04-16 16:09:44.704 731 1589 W ActivityManager: Force finishing activity com.cyngn.theme.chooser/.ChooserActivity
04-16 16:09:44.705 731 1589 W ActivityManager: Force finishing activity com.android.settings/.Settings
04-16 16:09:44.710 3590 3590 D AndroidRuntime: Shutting down VM

The thing is that there is no such folder on the original system partition of COS13....

*EDIT*

Nevermind, the error is not connected to the missing libs (/system/priv-app/ThemeChooser/lib/arm). This is also the case on STOCK COS13...

*EDIT2*

It looks like the Theme thingy will be the problematic part like before.