Add error message in case data files in resources could not be found

src/main/java/emu/grasscutter/data/DataLoader.java

@@ -51,13 +51,17 @@ public class DataLoader {
         try {
             List<Path> filenames = FileUtils.getPathsFromResource("/defaults/data/");
             
+            if (filenames == null) {
+            	Grasscutter.getLogger().error("We were unable to locate your default data files.");
+            }
+
             for (Path file : filenames) {
                 String relativePath = String.valueOf(file).split("defaults[\\\\\\/]data[\\\\\\/]")[1];
 
                 CheckAndCopyData(relativePath);
             }
         } catch (Exception e) {
-            Grasscutter.getLogger().error("An error occurred while trying to check the data folder. \n", e);
+            Grasscutter.getLogger().error("An error occurred while trying to check the data folder.", e);
         }
 
         GenerateGachaMappings();

src/main/java/emu/grasscutter/utils/FileUtils.java

@@ -9,6 +9,7 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.*;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -97,6 +98,11 @@ public final class FileUtils {
 		} catch (Exception e) {
 			// Eclipse puts resources in its bin folder
 			File f = new File(jarPath + "defaults/data/");
+			
+			if (!f.exists() || f.listFiles().length == 0) {
+				return null;
+			}
+			
 			result = Arrays.stream(f.listFiles()).map(File::toPath).toList();
 		}