Do I know if I need Multi-Dex enabled? (ClassNotFoundException)

Question

Suddenly and seemingly for no reason at all, the following error starts presenting itself. After fighting it all day, I discovered enabling Multi-Dex resolved it. Is this er

Answer 1

First, you can count the method references (and see other useful insight) using the APK Analyzer tool. It is shipped with Android Studio; you can find it under the Build menu and it's also available from the command line with apkanalyzer.

Second, you will get a build error indicating you need to use multi dex. It looks like:

trouble writing output: Too many field references: 131000; max is 65536. You may try using --multi-dex option.

More here: https://developer.android.com/studio/build/multidex.html

Answer 2

java.lang.ClassNotFoundException: Didn't find class

This is a known issue in the creation of the Java classes.zip file in the following release:

December 4th, 2017 - Xamarin.Android 8.1.0.24

• This version is included in the Visual Studio 2017 version 15.5 release.

Java.lang.ClassNotFoundException

We have had multiple reports regarding applications running into a "Java.Lang.ClassNotFoundException: Didn't find class on path: DexPathList" exception.

Bug: xamarin.android_8.1/#Known_Issues

GitHub PR fix: https://github.com/xamarin/xamarin-android/pull/1142

Workaround:

You can clean/rebuild as a workaround on Windows in order to recreate the Java classes.zip file