diff --git a/src/loader.py b/src/loader.py
index 0eb97d8..7b1e3c2 100644
--- a/src/loader.py
+++ b/src/loader.py
@@ -37,19 +37,19 @@ def version_check(configuration: dict, pkg_name: str) -> int:
             return 0
         with open(f"{disk}/PEinjector/VERSION", 'r', encoding="utf-8") as f:
             version = f.readlines()[0].rstrip("\n\r")
-            
+
         if "min" in configuration["compatibility"]["injector"]:
             plugver = configuration["compatibility"]["injector"]["min"]
             if __version_compare(version, plugver) == -1:
                 log.warn(ERROR_MESSAGE.format(pkg_name, "low", plugver))
                 return 5
-            
+
         if "max" in configuration["compatibility"]["injector"]:
             plugver = configuration["compatibility"]["injector"]["max"]
             if __version_compare(version, plugver) == 1:
                 log.warn(ERROR_MESSAGE.format(pkg_name, "high", plugver))
                 return 6
-            
+
     except Exception as e:
         log.warn(f"load moudle [{pkg_name}] failed: {e}")
         return 7
@@ -57,21 +57,16 @@ def version_check(configuration: dict, pkg_name: str) -> int:
 
 def file_check(file_json, pkg_name):
     try:
-        if "compatibility" in file_json:
-            if "file" in file_json["compatibility"]:
-                if "must" in file_json["compatibility"]["file"]:
-                    for i in file_json["compatibility"]["file"]["must"]:
-                        if not os.path.exists(i):
-                            log.warn(f"load moudle [{pkg_name}] failed: " +
-                                     f"Cannot find file: [{i}]")
-                            return 8
-                if "mustnot" in file_json["compatibility"]["file"]:
-                    for i in file_json["compatibility"]["file"]["mustnot"]:
-                        if os.path.exists(i):
-                            log.warn(f"load moudle [{pkg_name}] failed: " +
-                                     f"Find incompatible file: [{i}]")
-                            return 9
-
+        for i in file_json.get("compatibility", {}).get("file", {}).get("must", []):
+            if not os.path.exists(i):
+                log.warn(f"load moudle [{pkg_name}] failed: " +
+                         f"Cannot find file: [{i}]")
+                return 8
+        for i in file_json.get("compatibility", {}).get("file", {}).get("mustnot", []):
+            if os.path.exists(i):
+                log.warn(f"load moudle [{pkg_name}] failed: " +
+                         f"Find incompatible file: [{i}]")
+                return 9
     except:
         log.warn(f"load moudle [{pkg_name}] failed: " +
                  "Unknown error in file check")
@@ -91,17 +86,15 @@ def load_package(pkg_name):
         return 1
     try:
         with open(pkg_path+"/"+"manifest.json", "r", encoding="utf-8") as file:
-            file_str = file.read()
+            file_json = json.load(json.decoder.JSONDecodeError)
+    except json.decoder.JSONDecodeError:
+        log.warn(f"load moudle [{pkg_name}] failed: " +
+                 "Json syntax error")
+        return 3
     except Exception as exp:
         log.warn(f"load moudle [{pkg_name}] failed: " +
                  "Unknown error in read file ("+repr(exp)+")")
         return 2
-    try:
-        file_json = json.loads(file_str)
-    except:
-        log.warn(f"load moudle [{pkg_name}] failed: " +
-                 "Json syntax error")
-        return 3
     for i in ("version", "name", "author", "introduce"):
         if i not in file_json:
             log.warn(f"load moudle [{pkg_name}] failed: " +