Fix verify invalid json

src/Content/ContentManager.py

@@ -936,10 +936,13 @@ class ContentManager(object):
                 if type(file) is dict:
                     new_content = file
                 else:
+                    try:
                         if sys.version_info.major == 3 and sys.version_info.minor < 6:
                             new_content = json.loads(file.read().decode("utf8"))
                         else:
                             new_content = json.load(file)
+                    except Exception as err:
+                        raise VerifyError("Invalid json file: %s" % err)
                 if inner_path in self.contents:
                     old_content = self.contents.get(inner_path, {"modified": 0})
                     # Checks if its newer the ours