diff --git a/MMOCore-API/src/main/java/net/Indyuce/mmocore/api/util/MMOCoreUtils.java b/MMOCore-API/src/main/java/net/Indyuce/mmocore/api/util/MMOCoreUtils.java
index c0a140dd..103ebbe6 100644
--- a/MMOCore-API/src/main/java/net/Indyuce/mmocore/api/util/MMOCoreUtils.java
+++ b/MMOCore-API/src/main/java/net/Indyuce/mmocore/api/util/MMOCoreUtils.java
@@ -128,8 +128,8 @@ public class MMOCoreUtils {
      * @param message Message to display
      */
     public static void displayIndicator(Location loc, String message) {
-        Hologram holo = Hologram.create(loc, Arrays.asList(message));
-        Bukkit.getScheduler().runTaskLater(MMOCore.plugin, () -> holo.despawn(), 20);
+        Hologram holo = Hologram.create(loc, Collections.singletonList(message));
+        Bukkit.getScheduler().runTaskLater(MMOCore.plugin, holo::despawn, 20);
     }
 
     public static boolean isPlayerHead(Material material) {
diff --git a/MMOCore-API/src/main/java/net/Indyuce/mmocore/experience/PlayerProfessions.java b/MMOCore-API/src/main/java/net/Indyuce/mmocore/experience/PlayerProfessions.java
index 28e0fb9d..956453ac 100644
--- a/MMOCore-API/src/main/java/net/Indyuce/mmocore/experience/PlayerProfessions.java
+++ b/MMOCore-API/src/main/java/net/Indyuce/mmocore/experience/PlayerProfessions.java
@@ -155,11 +155,11 @@ public class PlayerProfessions {
         return profession.hasMaxLevel() && getLevel(profession) >= profession.getMaxLevel();
     }
 
-    public void giveExperience(Profession profession, double value, EXPSource source) {
+    public void giveExperience(@NotNull Profession profession, double value, @NotNull EXPSource source) {
         giveExperience(profession, value, source, null, true);
     }
 
-    public void giveExperience(Profession profession, double value, EXPSource source, @Nullable Location hologramLocation, boolean splitExp) {
+    public void giveExperience(@NotNull Profession profession, double value, @NotNull EXPSource source, @Nullable Location hologramLocation, boolean splitExp) {
         Validate.isTrue(playerData.isOnline(), "Cannot give experience to offline player");
         if (value <= 0) {
             exp.put(profession.getId(), Math.max(0, exp.getOrDefault(profession.getId(), 0d) + value));
@@ -190,7 +190,7 @@ public class PlayerProfessions {
             return;
 
         // Display hologram
-        if (hologramLocation != null)
+        if (hologramLocation != null && profession.getOption(Profession.ProfessionOption.EXP_HOLOGRAMS))
             MMOCoreUtils.displayIndicator(hologramLocation.add(.5, 1.5, .5), ConfigMessage.fromKey("exp-hologram", "exp", MythicLib.plugin.getMMOConfig().decimal.format(event.getExperience())).asLine());
 
         exp.put(profession.getId(), Math.max(0, exp.getOrDefault(profession.getId(), 0d) + event.getExperience()));
@@ -228,10 +228,10 @@ public class PlayerProfessions {
             playerData.getStats().updateStats();
         }
 
-        StringBuilder bar = new StringBuilder("" + ChatColor.BOLD);
+        StringBuilder bar = new StringBuilder(ChatColor.BOLD.toString());
         int chars = (int) (exp / needed * 20);
         for (int j = 0; j < 20; j++)
-            bar.append(j == chars ? "" + ChatColor.WHITE + ChatColor.BOLD : "").append("|");
+            bar.append(j == chars ? ChatColor.WHITE.toString() + ChatColor.BOLD : "").append("|");
         if (playerData.isOnline())
             ConfigMessage.fromKey("exp-notification", "profession", profession.getName(), "progress", bar.toString(), "ratio",
                     MythicLib.plugin.getMMOConfig().decimal.format(exp / needed * 100)).send(playerData.getPlayer());
diff --git a/MMOCore-API/src/main/java/net/Indyuce/mmocore/experience/Profession.java b/MMOCore-API/src/main/java/net/Indyuce/mmocore/experience/Profession.java
index a5d8dbc7..9ac2cc2a 100644
--- a/MMOCore-API/src/main/java/net/Indyuce/mmocore/experience/Profession.java
+++ b/MMOCore-API/src/main/java/net/Indyuce/mmocore/experience/Profession.java
@@ -124,8 +124,7 @@ public class Profession extends PostLoadObject implements ExperienceObject {
     }
 
     @Override
-    public void giveExperience(PlayerData playerData, double experience, @Nullable Location hologramLocation, EXPSource source) {
-        hologramLocation = !getOption(Profession.ProfessionOption.EXP_HOLOGRAMS) ? null : hologramLocation;
+    public void giveExperience(@NotNull PlayerData playerData, double experience, @Nullable Location hologramLocation, @NotNull EXPSource source) {
         playerData.getCollectionSkills().giveExperience(this, experience, EXPSource.SOURCE, hologramLocation, true);
     }
 
diff --git a/MMOCore-API/src/main/java/net/Indyuce/mmocore/loot/chest/RegionBounds.java b/MMOCore-API/src/main/java/net/Indyuce/mmocore/loot/chest/RegionBounds.java
index 5b5cf8de..b2949d70 100644
--- a/MMOCore-API/src/main/java/net/Indyuce/mmocore/loot/chest/RegionBounds.java
+++ b/MMOCore-API/src/main/java/net/Indyuce/mmocore/loot/chest/RegionBounds.java
@@ -19,7 +19,7 @@ public class RegionBounds {
 
 		String name = config.getString("world");
 		Validate.notNull(name, "Could not find world name");
-		Validate.notNull(world = Bukkit.getWorld(name), "Could not find world " + config.getString("world"));
+		Validate.notNull(world = Bukkit.getWorld(name), "Could not find world '" + config.getString("world") + "'");
 
 		x1 = Math.min(config.getInt("x1"), config.getInt("x2"));
 		x2 = Math.max(config.getInt("x1"), config.getInt("x2"));
diff --git a/MMOCore-API/src/main/java/net/Indyuce/mmocore/manager/profession/CustomBlockManager.java b/MMOCore-API/src/main/java/net/Indyuce/mmocore/manager/profession/CustomBlockManager.java
index acbe4061..cbdd0ec4 100644
--- a/MMOCore-API/src/main/java/net/Indyuce/mmocore/manager/profession/CustomBlockManager.java
+++ b/MMOCore-API/src/main/java/net/Indyuce/mmocore/manager/profession/CustomBlockManager.java
@@ -69,7 +69,7 @@ public class CustomBlockManager extends SpecificProfessionManager {
 	 * @return       The new block behaviour or null if no new behaviour
 	 */
 	public @Nullable BlockInfo getInfo(Block block) {
-		return map.getOrDefault(findBlockType(block).generateKey(), null);
+		return map.get(findBlockType(block).generateKey());
 	}
 
 	public BlockType findBlockType(Block block) {