diff --git a/ckanext/odsh/lib/uploader.py b/ckanext/odsh/lib/uploader.py
index fa338656771af5b186f4425b9241f6ba31d74909..65def18c25e1db0adc2ee66bb3e3364dbb5689a1 100644
--- a/ckanext/odsh/lib/uploader.py
+++ b/ckanext/odsh/lib/uploader.py
@@ -29,6 +29,7 @@ def raise_validation_error_if_virus_found(filename, upload_file):
 
 
 def calculate_hash(upload_file):
+    upload_file.seek(0)
     hash_md5 = hashlib.md5()
     for chunk in iter(lambda: upload_file.read(4096), b""):
             hash_md5.update(chunk)
@@ -41,6 +42,8 @@ def _raise_validation_error_if_hash_values_differ(upload_file, resource):
     if hash_from_resource:
         hash_from_calculation = calculate_hash(upload_file)
         if not hash_from_calculation == hash_from_resource:
+            log.debug('hash from calculation: {}'.format(hash_from_calculation))
+            log.debug('hash from resource: {}'.format(hash_from_resource))
             raise logic.ValidationError({'upload': ['Berechneter Hash und mitgelieferter Hash sind unterschiedlich']})
             
 
diff --git a/ckanext/odsh/plugin.py b/ckanext/odsh/plugin.py
index 3dfc22ab246746e60cb7c1f9cc232f779e5e7e66..a97dcbeaf1bc4cd7aeff64a118111b4c283bccc3 100644
--- a/ckanext/odsh/plugin.py
+++ b/ckanext/odsh/plugin.py
@@ -111,7 +111,6 @@ class OdshPlugin(plugins.SingletonPlugin, DefaultTranslation, DefaultDatasetForm
         schema['extras'].update({
             'key': [
                 toolkit.get_converter('known_spatial_uri'),
-                toolkit.get_converter('validate_licenseAttributionByText'),
             ]
         })
         schema.update(