diff --git a/SPD-classes/src/main/java/com/watabou/gltextures/TextureCache.java b/SPD-classes/src/main/java/com/watabou/gltextures/TextureCache.java
index cba664a27..b092bde56 100644
--- a/SPD-classes/src/main/java/com/watabou/gltextures/TextureCache.java
+++ b/SPD-classes/src/main/java/com/watabou/gltextures/TextureCache.java
@@ -44,7 +44,7 @@ public class TextureCache {
 		bitmapOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;
 	}
 
-	public static SmartTexture createSolid( int color ) {
+	public synchronized static SmartTexture createSolid( int color ) {
 		final String key = "1x1:" + color;
 		
 		if (all.containsKey( key )) {
@@ -63,7 +63,7 @@ public class TextureCache {
 		}
 	}
 	
-	public static SmartTexture createGradient( int... colors ) {
+	public synchronized static SmartTexture createGradient( int... colors ) {
 		
 		final String key = "" + colors;
 		
@@ -88,11 +88,11 @@ public class TextureCache {
 		
 	}
 	
-	public static void add( Object key, SmartTexture tx ) {
+	public synchronized static void add( Object key, SmartTexture tx ) {
 		all.put( key, tx );
 	}
 	
-	public static void remove( Object key ){
+	public synchronized static void remove( Object key ){
 		SmartTexture tx = all.get( key );
 		if (tx != null){
 			all.remove(key);
@@ -100,7 +100,7 @@ public class TextureCache {
 		}
 	}
 
-	public static SmartTexture get( Object src ) {
+	public synchronized static SmartTexture get( Object src ) {
 		
 		if (all.containsKey( src )) {
 			
@@ -119,17 +119,17 @@ public class TextureCache {
 		
 	}
 	
-	public static void clear() {
+	public synchronized static void clear() {
 		
-		for (Texture txt:all.values()) {
+		for (Texture txt : all.values()) {
 			txt.delete();
 		}
 		all.clear();
 		
 	}
 	
-	public static void reload() {
-		for (SmartTexture tx:all.values()) {
+	public synchronized static void reload() {
+		for (SmartTexture tx : all.values()) {
 			tx.reload();
 		}
 	}
@@ -164,7 +164,7 @@ public class TextureCache {
 		}
 	}
 	
-	public static boolean contains( Object key ) {
+	public synchronized static boolean contains( Object key ) {
 		return all.containsKey( key );
 	}
 	
diff --git a/SPD-classes/src/main/java/com/watabou/noosa/Group.java b/SPD-classes/src/main/java/com/watabou/noosa/Group.java
index 5d792ef3d..8756973e7 100644
--- a/SPD-classes/src/main/java/com/watabou/noosa/Group.java
+++ b/SPD-classes/src/main/java/com/watabou/noosa/Group.java
@@ -51,8 +51,10 @@ public class Group extends Gizmo {
 			}
 		}
 		
-		members.clear();
-		members = null;
+		if (members != null) {
+			members.clear();
+			members = null;
+		}
 		length = 0;
 	}
 	
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/blobs/WaterOfHealth.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/blobs/WaterOfHealth.java
index a192489de..bbf8bf5b8 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/blobs/WaterOfHealth.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/blobs/WaterOfHealth.java
@@ -42,6 +42,8 @@ public class WaterOfHealth extends WellWater {
 	@Override
 	protected boolean affectHero( Hero hero ) {
 		
+		if (!hero.isAlive()) return false;
+		
 		Sample.INSTANCE.play( Assets.SND_DRINK );
 
 		hero.HP = hero.HT;
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/Mimic.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/Mimic.java
index 7b7d5dfd8..e19e1d277 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/Mimic.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/Mimic.java
@@ -62,14 +62,16 @@ public class Mimic extends Mob {
 	@Override
 	public void storeInBundle( Bundle bundle ) {
 		super.storeInBundle( bundle );
-		bundle.put( ITEMS, items );
+		if (items != null) bundle.put( ITEMS, items );
 		bundle.put( LEVEL, level );
 	}
 	
 	@SuppressWarnings("unchecked")
 	@Override
 	public void restoreFromBundle( Bundle bundle ) {
-		items = new ArrayList<>( (Collection<Item>) ((Collection<?>) bundle.getCollection( ITEMS ) ));
+		if (bundle.contains( ITEMS )) {
+			items = new ArrayList<>((Collection<Item>) ((Collection<?>) bundle.getCollection(ITEMS)));
+		}
 		adjustStats( bundle.getInt( LEVEL ) );
 		super.restoreFromBundle(bundle);
 	}
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/traps/SummoningTrap.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/traps/SummoningTrap.java
index 2025643f2..6f05f24ff 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/traps/SummoningTrap.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/levels/traps/SummoningTrap.java
@@ -77,10 +77,12 @@ public class SummoningTrap extends Trap {
 
 		for (Integer point : respawnPoints) {
 			Mob mob = Dungeon.level.createMob();
-			mob.state = mob.WANDERING;
-			mob.pos = point;
-			GameScene.add( mob, DELAY );
-			mobs.add( mob );
+			if (mob != null) {
+				mob.state = mob.WANDERING;
+				mob.pos = point;
+				GameScene.add(mob, DELAY);
+				mobs.add(mob);
+			}
 		}
 
 		//important to process the visuals and pressing of cells last, so spawned mobs have a chance to occupy cells first
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/windows/WndAlchemy.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/windows/WndAlchemy.java
index 76c5672dc..1bbf7cf73 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/windows/WndAlchemy.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/windows/WndAlchemy.java
@@ -302,7 +302,7 @@ public class WndAlchemy extends Window {
 	public void destroy() {
 		synchronized ( inputs ) {
 			for (int i = 0; i < inputs.length; i++) {
-				if (inputs[i].item != null) {
+				if (inputs[i] != null && inputs[i].item != null) {
 					if (!inputs[i].item.collect()) {
 						Dungeon.level.drop(inputs[i].item, Dungeon.hero.pos);
 					}
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/windows/WndBag.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/windows/WndBag.java
index f1fd6e2a7..6ff77103b 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/windows/WndBag.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/windows/WndBag.java
@@ -213,7 +213,7 @@ public class WndBag extends WndTabbed {
 		}
 
 		// Items in the bag
-		for (Item item : container.items) {
+		for (Item item : container.items.toArray(new Item[0])) {
 			placeItem( item );
 		}