diff --git a/kheops/controllers.py b/kheops/controllers.py
index 834ad00..99c1d21 100644
--- a/kheops/controllers.py
+++ b/kheops/controllers.py
@@ -266,7 +266,7 @@ class QueryProcessor:
                 lookup["path"] = new_path
                 new_lookups3.append(lookup)
             else:
-                log.info("Ignore because of missing scope vars: '%s'", path)
+                log.warning("Ignore lookup item because of missing scope vars: '%s'", path)
 
         return new_lookups3
 
diff --git a/kheops/plugin/backend/file.py b/kheops/plugin/backend/file.py
index f9b86c4..c251a98 100644
--- a/kheops/plugin/backend/file.py
+++ b/kheops/plugin/backend/file.py
@@ -32,7 +32,7 @@ class Plugin(BackendPlugin):
             "description": "This backend will look for data inside a file hierarchy.",
             "type": "object",
             "properties": {
-                "format": {
+                "extensions": {
                         "title": "File formats",
                         "description": """
                         This object describe which parser is assigned to which extension. 
@@ -124,19 +124,24 @@ class Plugin(BackendPlugin):
 
         raw_data = None
         status = "not_found"
-        for ext, parser in self.extensions.items():
+        extensions = self.config.get("extensions", self.extensions)
+        for ext, parser in extensions.items():
             new_path = os.path.join(self.top_path, path + ext)
-            log.debug("Looking into %s", new_path)
             if os.path.isfile(new_path):
                 status = "found"
                 try:
+                    log.info("Found file: %s", new_path)
                     raw_data = anyconfig.load(new_path, ac_parser=parser)
                 except AnyConfigBaseError as err:
                     status = "broken"
                     raw_data = None
                     log.warning("Could not parse file %s: %s", new_path, err)
+
+                # Stop the loop extension if we found a result.
                 break
 
+            log.debug("Skip absent file: %s", new_path)
+
         ret = BackendCandidate(
             path=new_path,
             status=status,
diff --git a/kheops/plugin/common.py b/kheops/plugin/common.py
index a1ba393..c0105a1 100644
--- a/kheops/plugin/common.py
+++ b/kheops/plugin/common.py
@@ -35,7 +35,8 @@ class KheopsPlugin:
         self.config = self.ns.config["config"].get(config_key, {})
         self.config_key = config_key
 
-        log.debug("Looking for plugin configuration in config with key '%s', got: %s", config_key, self.config)
+        #if self.config:
+        #    log.debug("Load plugin configuration in config with key '%s', got: %s", config_key, self.config)
         self._init()
 
     def _init(self):
diff --git a/kheops/plugin/scope/loop.py b/kheops/plugin/scope/loop.py
index 2c1153f..2ac3092 100644
--- a/kheops/plugin/scope/loop.py
+++ b/kheops/plugin/scope/loop.py
@@ -12,7 +12,7 @@ log = logging.getLogger(__name__)
 class Plugin(ScopePlugin, ScopeExtLoop):
     """Hierarchy plugin"""
 
-    _plugin_name = "hier"
+    plugin_name = "hier"
     _schema_props_new = {
         "hier": {
             "default": None,