--- a/net/minecraft/server/packs/PathPackResources.java
+++ b/net/minecraft/server/packs/PathPackResources.java
@@ -108,6 +108,12 @@
         try (DirectoryStream<Path> directoryStream = Files.newDirectoryStream(path)) {
             for(Path path2 : directoryStream) {
                 String string = path2.getFileName().toString();
+                // Paper start
+                if (!Files.isDirectory(path2)) {
+                    LOGGER.error("Invalid directory entry: {} in {}.", string, this.root, new java.nio.file.NotDirectoryException(string));
+                    continue;
+                }
+                // Paper end
                 if (ResourceLocation.isValidNamespace(string)) {
                     set.add(string);
                 } else {
