commit 8fcd8cba3659d4551d3051c9f7834e51e8e53307
Author: Leszek Koltunski <leszek@koltunski.pl>
Date:   Mon Apr 13 11:37:11 2020 +0100

    1) Relax requirements as to OpenGL ES ( now only 3.0 required )
    2) fix a crash in Solving state

diff --git a/src/main/AndroidManifest.xml b/src/main/AndroidManifest.xml
index 3759d7d4..1e0bf344 100644
--- a/src/main/AndroidManifest.xml
+++ b/src/main/AndroidManifest.xml
@@ -1,7 +1,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="org.distorted.main">
 
-    <uses-feature android:glEsVersion="0x00030001" android:required="true" />
+    <uses-feature android:glEsVersion="0x00030000" android:required="true" />
     <uses-feature android:name="android.hardware.faketouch" android:required="true" />
     <uses-feature android:name="android.hardware.touchscreen" android:required="false" />
 
diff --git a/src/main/java/org/distorted/states/RubikStateSolving.java b/src/main/java/org/distorted/states/RubikStateSolving.java
index eef0f349..7fd6e439 100644
--- a/src/main/java/org/distorted/states/RubikStateSolving.java
+++ b/src/main/java/org/distorted/states/RubikStateSolving.java
@@ -211,6 +211,8 @@ public class RubikStateSolving extends RubikStateAbstract implements RubikPostRe
 
   public void savePreferences(SharedPreferences.Editor editor)
     {
+    mPrevButton = null;
+
     mScores.savePreferences(editor);
     }