We need to catch some rares exceptions !

src/main/java/fr/xephi/authme/cache/backup/FileCache.java

@@ -38,6 +38,8 @@ public class FileCache {
     public void createCache(Player player, DataFileCache playerData,
             String group, boolean operator, boolean flying) {
         String path = "";
+        if (player == null)
+        	return;
         try {
             path = player.getUniqueId().toString();
         } catch (Exception e) {

src/main/java/fr/xephi/authme/cache/limbo/LimboCache.java

@@ -48,9 +48,14 @@ public class LimboCache {
                 inv = null;
                 arm = null;
             }
-            playerGroup = playerData.readCache(player).getGroup();
-            operator = playerData.readCache(player).getOperator();
-            flying = playerData.readCache(player).isFlying();
+            try {
+                playerGroup = playerData.readCache(player).getGroup();
+                operator = playerData.readCache(player).getOperator();
+                flying = playerData.readCache(player).isFlying();
+            } catch (Exception e)
+            {
+            	ConsoleLogger.showError("Some error on reading cache of " + name);
+            }
         } else {
             StoreInventoryEvent event = new StoreInventoryEvent(player);
             Bukkit.getServer().getPluginManager().callEvent(event);