diff --git a/backend/core/file.go b/backend/core/file.go
index e60998c..051eb58 100644
--- a/backend/core/file.go
+++ b/backend/core/file.go
@@ -2,6 +2,7 @@ package core
 
 import (
 	"backend/util"
+	"errors"
 	"io/fs"
 	"os"
 	"strings"
@@ -60,17 +61,16 @@ func getFileInfo(info fs.FileInfo, picd []PictureData, actualdir string) []Pictu
 	return picd
 }
 
-func ListFiles(path string) []PictureData {
+func ListFiles(path string) ([]PictureData, error) {
 	var picd []PictureData
-	picd = listFiles(path, "", picd)
 	start := time.Now()
-	print("\n")
+	picd = listFiles(path, "", picd)
 	if len(picd) == 0 {
-		util.Logformat(util.ERROR, "Could not gather any file.\n")
-		return nil
+		return nil, errors.New("ListFiles(): Could not gather any file")
 	} else {
 		elapsed := time.Since(start)
+		print("\n")
 		util.Logformat(util.CORRECT, "Gathered %d files in %dms.\n", len(picd), elapsed.Milliseconds())
-		return picd
+		return picd, nil
 	}
 }
diff --git a/backend/go.mod b/backend/go.mod
index 9be7739..4164d1a 100644
--- a/backend/go.mod
+++ b/backend/go.mod
@@ -1,3 +1,3 @@
 module backend
 
-go 1.24.2
+go 1.23.6
diff --git a/backend/main.go b/backend/main.go
index 690bdcd..0d9947c 100644
--- a/backend/main.go
+++ b/backend/main.go
@@ -20,13 +20,17 @@ func main() {
 			cfg, _ = util.ReadConfig("config.json")
 		} else {
 			util.Logformat(util.ERROR, "Could not read configuration file: %s\n", err.Error())
-			panic(err)
+			os.Exit(2)
 		}
 	}
 
 	// Reading files
 	util.Logformat(util.INFO, "Reading folder '%s'\n", cfg.PhotoPath)
-	core.ListFiles(cfg.PhotoPath)
+	_, err = core.ListFiles(cfg.PhotoPath)
+	if err != nil {
+		util.Logformat(util.ERROR, "%s\n", err.Error())
+		os.Exit(3)
+	}
 
 	// Rest API start on port
 	server.Start(8085)
diff --git a/backend/util/config.go b/backend/util/config.go
index 7405c3b..1e50275 100644
--- a/backend/util/config.go
+++ b/backend/util/config.go
@@ -19,6 +19,7 @@ func ReadConfig(path string) (Config, error) {
 	defer file.Close()
 
 	decoder := json.NewDecoder(file)
+	decoder.DisallowUnknownFields()
 	err = decoder.Decode(&cfg)
 	return cfg, err
 }