Old gvr project crashes on android (worked in 5.5, crashes on 2017.4 build)

Just posting here for future googlers..

Tested upgrading old 5.5 cardboard vr project into 2017.4.0f1 LTS, and all went fine,
except that Android build crashes on start, with the error below:

(iOS build works fine, and that error is probably caused by old GVR plugin v0.7,
so going to check later if upgrading that helps..)

Code (CSharp):

1. java.lang.Error: FATAL EXCEPTION [main]
2.  
3. E/AndroidRuntime(10577): Caused by: java.lang.NoSuchMethodError: No direct method <init>(Landroid/content/ContextWrapper;)V in class Lcom/unity3d/player/UnityPlayer; or its super classes (declaration of 'com.unity3d.player.UnityPlayer' appears in /data/app/com.xyz.asdasd-2/base.apk)
4. E/AndroidRuntime(10577):        at com.google.unity.GoogleUnityActivity.onCreate(GoogleUnityActivity.java:114)
5. E/AndroidRuntime(10577):        at android.app.Activity.performCreate(Activity.java:6289)
6. E/AndroidRuntime(10577):        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
7. E/AndroidRuntime(10577):        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2655)
8. E/AndroidRuntime(10577):        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2767)
9. E/AndroidRuntime(10577):        at android.app.ActivityThread.access$900(ActivityThread.java:177)
10. E/AndroidRuntime(10577):        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1449)
11. E/AndroidRuntime(10577):        at android.os.Handler.dispatchMessage(Handler.java:102)
12. E/AndroidRuntime(10577):        at android.os.Looper.loop(Looper.java:145)
13. E/AndroidRuntime(10577):        at android.app.ActivityThread.main(ActivityThread.java:5951)
14. E/AndroidRuntime(10577):        at java.lang.reflect.Method.invoke(Native Method)
15. E/AndroidRuntime(10577):        at java.lang.reflect.Method.invoke(Method.java:372)
16. E/AndroidRuntime(10577):        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
17. E/AndroidRuntime(10577):        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
18.  
19.  

*similar topics, no working answers though
https://forum.unity.com/threads/for...e-your-google-vr-sdk-to-1-12-or-later.520986/ *i'm not using il2cpp though
https://forum.unity.com/threads/crash-in-unity-2017-com-unity3d-player-unityplayer.492450/
https://answers.unity.com/questions/1389155/i-built-a-google-daydream-vr-game-in-unity-but-whe.html
https://answers.unity.com/questions/848333/android-plugin-context-issues.html
https://answers.unity.com/questions/930466/unity-android-plugin-no-method-with-name.html
https://answers.unity.com/questions/1274789/project-tange-unfortunately-app-name-has-stopped.html

 

yes, confirmed that removing those old gvr files from plugin folder allowed the app to start.

although was hoping that could still use the old version, as there is some code that relies on the old cardboard button stuff etc.. but i guess need to update eventually anyways.