diff --git a/server/common/app_config.py b/server/common/app_config.py
index 36f27ea4..f1dc942b 100644
--- a/server/common/app_config.py
+++ b/server/common/app_config.py
@@ -459,6 +459,7 @@ class ServerConfig(BaseConfig):
 
     def complete_config(self, context):
         self.handle_app(context)
+        self.handle_data_source(context)
         self.handle_authentication(context)
         self.handle_data_locator(context)
         self.handle_adaptor(context)  # may depend on data_locator
@@ -572,12 +573,9 @@ class ServerConfig(BaseConfig):
                 region_name = None
             self.data_locator__s3__region_name = region_name
 
-    def handle_single_dataset(self, context):
+    def handle_data_source(self, context):
         self.check_attr("single_dataset__datapath", (str, type(None)))
-        self.check_attr("single_dataset__title", (str, type(None)))
-        self.check_attr("single_dataset__about", (str, type(None)))
-        self.check_attr("single_dataset__obs_names", (str, type(None)))
-        self.check_attr("single_dataset__var_names", (str, type(None)))
+        self.check_attr("multi_dataset__dataroot", (type(None), dict, str))
 
         if self.single_dataset__datapath is None:
             if self.multi_dataset__dataroot is None:
@@ -588,6 +586,16 @@ class ServerConfig(BaseConfig):
             if self.multi_dataset__dataroot is not None:
                 raise ConfigurationError("must supply only one of datapath or dataroot")
 
+    def handle_single_dataset(self, context):
+        self.check_attr("single_dataset__datapath", (str, type(None)))
+        self.check_attr("single_dataset__title", (str, type(None)))
+        self.check_attr("single_dataset__about", (str, type(None)))
+        self.check_attr("single_dataset__obs_names", (str, type(None)))
+        self.check_attr("single_dataset__var_names", (str, type(None)))
+
+        if self.single_dataset__datapath is None:
+            return
+
         # create the matrix data cache manager:
         if self.matrix_data_cache_manager is None:
             self.matrix_data_cache_manager = MatrixDataCacheManager(max_cached=1, timelimit_s=None)
diff --git a/server/eb/app.py b/server/eb/app.py
index 0c8d00ae..933277ec 100644
--- a/server/eb/app.py
+++ b/server/eb/app.py
@@ -102,7 +102,8 @@ class WSGIServer(Server):
 
         # It is _very_ difficult to generate the correct hash manually,
         # consider forcing CSP to fail on the local server by intercepting the response via Requestly
-        # this should print the failing script's hash to console. See more here: https://github.com/chanzuckerberg/cellxgene/pull/1745
+        # this should print the failing script's hash to console.
+        # See more here: https://github.com/chanzuckerberg/cellxgene/pull/1745
         obsolete_browser_script_hash = ["'sha256-/rmgOi/skq9MpiZxPv6lPb1PNSN+Uf4NaUHO/IjyfwM='"]
         csp = {
             "default-src": ["'self'"],