diff --git a/common/src/main/java/me/lucko/luckperms/commands/Util.java b/common/src/main/java/me/lucko/luckperms/commands/Util.java
index d1b2bc0e5..8256fd948 100644
--- a/common/src/main/java/me/lucko/luckperms/commands/Util.java
+++ b/common/src/main/java/me/lucko/luckperms/commands/Util.java
@@ -44,7 +44,7 @@ public class Util {
         if (strings.isEmpty()) return "&6None";
 
         StringBuilder sb = new StringBuilder();
-        strings.stream().forEach(s -> sb.append("&6").append(s).append("&7, "));
+        strings.forEach(s -> sb.append("&6").append(s).append("&7, "));
         return sb.delete(sb.length() - 2, sb.length()).toString();
     }
 
diff --git a/common/src/main/java/me/lucko/luckperms/data/methods/FlatfileDatastore.java b/common/src/main/java/me/lucko/luckperms/data/methods/FlatfileDatastore.java
index eb442e907..77016be36 100644
--- a/common/src/main/java/me/lucko/luckperms/data/methods/FlatfileDatastore.java
+++ b/common/src/main/java/me/lucko/luckperms/data/methods/FlatfileDatastore.java
@@ -319,9 +319,9 @@ public class FlatfileDatastore extends Datastore {
 
     @Override
     public boolean loadAllGroups() {
-        List<String> groups = Arrays.asList(groupsDir.list((dir, name1) -> name1.endsWith(".json")))
-                .stream().map(s -> s.substring(0, s.length() - 5))
-                .collect(Collectors.toList());
+        String[] fileNames = groupsDir.list((dir, name) -> name.endsWith(".json"));
+        if (fileNames == null) return false;
+        List<String> groups = Arrays.stream(fileNames).map(s -> s.substring(0, s.length() - 5)).collect(Collectors.toList());
 
         plugin.getGroupManager().unloadAll();
         groups.forEach(this::loadGroup);
diff --git a/common/src/main/java/me/lucko/luckperms/data/methods/MySQLDatastore.java b/common/src/main/java/me/lucko/luckperms/data/methods/MySQLDatastore.java
index 3be5cbf9b..1f8ae7dc8 100644
--- a/common/src/main/java/me/lucko/luckperms/data/methods/MySQLDatastore.java
+++ b/common/src/main/java/me/lucko/luckperms/data/methods/MySQLDatastore.java
@@ -50,7 +50,7 @@ public class MySQLDatastore extends SQLDatastore {
     @Override
     public void shutdown() {
         if (hikari != null) {
-            hikari.shutdown();
+            hikari.close();
         }
     }
 
diff --git a/common/src/main/java/me/lucko/luckperms/data/methods/SQLDatastore.java b/common/src/main/java/me/lucko/luckperms/data/methods/SQLDatastore.java
index edbb1875a..d1a382a0b 100644
--- a/common/src/main/java/me/lucko/luckperms/data/methods/SQLDatastore.java
+++ b/common/src/main/java/me/lucko/luckperms/data/methods/SQLDatastore.java
@@ -19,7 +19,6 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
-import java.util.logging.Level;
 
 @SuppressWarnings("UnnecessaryLocalVariable")
 abstract class SQLDatastore extends Datastore {
diff --git a/common/src/main/java/me/lucko/luckperms/users/User.java b/common/src/main/java/me/lucko/luckperms/users/User.java
index 16fb5c040..b9cff9f53 100644
--- a/common/src/main/java/me/lucko/luckperms/users/User.java
+++ b/common/src/main/java/me/lucko/luckperms/users/User.java
@@ -96,7 +96,7 @@ public abstract class User extends PermissionObject {
     /**
      * Remove the user from a group
      * @param group the group to remove the user from
-     * @throws ObjectLacksPermissionException
+     * @throws ObjectLacksPermissionException if the user isn't a member of the group
      */
     public void removeGroup(Group group) throws ObjectLacksPermissionException {
         removeGroup(group, "global");