fix: Add user friendly message for creationdate placeholder

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -27,10 +27,10 @@ body:
       description: Which server version version you using? If your server version is not listed, it is not supported. Update to a supported version first.
       multiple: false
       options:
-        - '1.19.1'
         - '1.19'
         - '1.18.2'
         - '1.18.1'
+        - '1.18'
         - '1.17.1'
         - '1.16.5'
     validations:

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());
 

Core/src/main/java/com/plotsquared/core/util/placeholders/PlaceholderRegistry.java

@@ -164,7 +164,7 @@ public final class PlaceholderRegistry {
                     PlayerManager.getPlayerList(plot.getDenied(), player));
         });
         this.createPlaceholder("currentplot_creationdate", (player, plot) -> {
-            if (plot.getTimestamp() == 0) {
+            if (plot.getTimestamp() == 0 || !plot.hasOwner()) {
                 return legacyComponent(TranslatableCaption.of("info.unknown"), player);
             }
             long creationDate = plot.getTimestamp();