In some cases the return value of yaml.load(description_text)

can be a string containing 'none'.

This will be fetched with isinstance(data, str)

osclib/stagingapi.py

@@ -698,7 +698,7 @@ class StagingAPI(object):
     def load_prj_pseudometa(self, description_text):
         try:
             data = yaml.load(description_text)
-            if data is None:
+            if isinstance(data, str) or data is None:
                 data = {}
         except (TypeError, AttributeError):
             data = {}