Hello,
I installed the plugin in a completely new project (i tried both Unity 5.5.1 and 5.6.1) added SampleNewUI scene to the Build settings and when i build and run to my Samsung Galaxy S6 (Android 7.0) and click on the OpenLocal button i get the following exception in the log:
06-13 16:48:14.430 13520-13535/? I/Unity: AndroidJavaException: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.PackageItemInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.PackageItemInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference
at android.support.v4.content.FileProvider.parsePathStrategy(FileProvider.java:561)
at android.support.v4.content.FileProvider.getPathStrategy(FileProvider.java:535)
at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:377)
at com.SlavaObninsk.pdfreader.Logic.OpenDocLocal(Logic.java:60)
at com.unity3d.player.UnityPlayer.nativeRender(Native Method)
at com.unity3d.player.UnityPlayer.a(Unknown Source)
at com.unity3d.player.UnityPlayer$b$1.handleMessage(Unknown Source)
Do you maybe have an idea what is going wrong there?