powder snow is 1.17+

Bukkit/src/main/java/com/plotsquared/bukkit/BukkitPlatform.java

@@ -656,15 +656,20 @@ public final class BukkitPlatform extends JavaPlugin implements Listener, PlotPl
             final @NonNull SQLiteUUIDService sqLiteUUIDService,
             final @NonNull CacheUUIDService cacheUUIDService
     ) {
-        // Record all unique UUID's and put them into a queue
-        final Set<UUID> uuidSet = new HashSet<>();
+        // Load all uuids into a big chunky boi queue
+        final Queue<UUID> uuidQueue = new LinkedBlockingQueue<>();
         PlotSquared.get().forEachPlotRaw(plot -> {
-            uuidSet.add(plot.getOwnerAbs());
-            uuidSet.addAll(plot.getMembers());
-            uuidSet.addAll(plot.getTrusted());
-            uuidSet.addAll(plot.getDenied());
+            final Set<UUID> uuids = new HashSet<>();
+            uuids.add(plot.getOwnerAbs());
+            uuids.addAll(plot.getMembers());
+            uuids.addAll(plot.getTrusted());
+            uuids.addAll(plot.getDenied());
+            for (final UUID uuid : uuids) {
+                if (!uuidQueue.contains(uuid)) {
+                    uuidQueue.add(uuid);
+                }
+            }
         });
-        final Queue<UUID> uuidQueue = new LinkedBlockingQueue<>(uuidSet);
 
         LOGGER.info("(UUID) {} UUIDs will be cached", uuidQueue.size());
 

Bukkit/src/main/java/com/plotsquared/bukkit/listener/BlockEventListener.java

@@ -121,6 +121,23 @@ public class BlockEventListener implements Listener {
             Material.TURTLE_EGG,
             Material.TURTLE_SPAWN_EGG
     );
+    private static final Set<Material> SNOW;  // needed as Tag.SNOW isn't present in 1.16.5
+
+    static {
+        if (PlotSquared.platform().serverVersion()[1] < 17) {
+            SNOW = Set.of(
+                    Material.SNOW,
+                    Material.SNOW_BLOCK
+            );
+        } else {
+            SNOW = Set.of(
+                    Material.SNOW,
+                    Material.SNOW_BLOCK,
+                    Material.POWDER_SNOW // only since 1.17
+            );
+        }
+    }
+
     private final PlotAreaManager plotAreaManager;
     private final WorldEdit worldEdit;
 
@@ -529,7 +546,7 @@ public class BlockEventListener implements Listener {
             event.setCancelled(true);
             return;
         }
-        if (Tag.SNOW.isTagged(event.getNewState().getType())) {
+        if (SNOW.contains(event.getNewState().getType())) {
             if (!plot.getFlag(SnowFormFlag.class)) {
                 plot.debug("Snow could not form because snow-form = false");
                 event.setCancelled(true);
@@ -561,7 +578,7 @@ public class BlockEventListener implements Listener {
             return;
         }
         Class<? extends BooleanFlag<?>> flag;
-        if (Tag.SNOW.isTagged(event.getNewState().getType())) {
+        if (SNOW.contains(event.getNewState().getType())) {
             flag = SnowFormFlag.class;
         } else if (Tag.ICE.isTagged(event.getNewState().getType())) {
             flag = IceFormFlag.class;
@@ -678,7 +695,7 @@ public class BlockEventListener implements Listener {
             }
             return;
         }
-        if (Tag.SNOW.isTagged(blockType)) {
+        if (SNOW.contains(blockType)) {
             if (!plot.getFlag(SnowMeltFlag.class)) {
                 plot.debug("Snow could not melt because snow-melt = false");
                 event.setCancelled(true);