XWalkView doesn't load downloaded files / local files and returns Assertion Error - crosswalk

Question

I am using this to implement crosswalk webview to my app
implementation 'org.xwalk:xwalk_core_library:23.53.589.4'
And I am setting up the XWalkView like this
private XWalkView xWalkWebView;
....
xWalkWebView=(XWalkView)findViewById(R.id.xwalkWebView);
and when I load an external HTML file like this, it loads fine
xWalkWebView.load("website.com/htmlfile.html",(String) null);
BUT when I try loading a local file it returns an error
xWalkWebView.load("file:///" + Environment.getExternalStorageDirectory().getAbsolutePath() + "/Download/File.html",(String) null);
The CrossWalk Activity crashes with a AssertionError warning and in some cases a NullPointerException
I have tried using XWalkView cache to store the data in its instance
xWalkWebView.clearCache(true);
xWalkWebView.getSettings().setCacheMode(XWalkSettings.LOAD_CACHE_ELSE_NETWORK);
xWalkWebView.reload(2);
It didn't work, and I also tried loadUrl, loadData, and loadDataWithBaseURL all of those didn't work trying to load a local file
I have tried a bunch of stuff like separating the function creating the XWalkView to a separate class to avoid the NullPointerException and a lot of other things but nothing worked and I am wondering if there is another function to load local files using XWalkView
Any help would be appreciated, thanks!
Edit: The Warning I am getting when the activity crashes is:
W/System.err: java.lang.AssertionError
at org.xwalk.core.internal.AndroidProtocolHandler.getAssetPath(AndroidProtocolHandler.java:82)
at org.xwalk.core.internal.XWalkMediaPlayerResourceLoadingFilter.shouldOverrideResourceLoading(XWalkMediaPlayerResourceLoadingFilter.java:38)
at org.chromium.media.MediaPlayerBridge.setDataSource(MediaPlayerBridge.java:205)
at org.chromium.base.SystemMessageHandler.nativeDoRunLoopOnce(Native Method)
at org.chromium.base.SystemMessageHandler.handleMessage(SystemMessageHandler.java:39)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4745)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)

Answer 1

I had the same problem. It was solved by modifying the Gradle version.
I think the highest Gradle version (currently 4.1.2) is not compatible with XWalkView. When I changed the Gradle version to 4.0.0, it works well.