diff --git a/awx/main/conf.py b/awx/main/conf.py
index 4e8e637eab..3f9a25a599 100644
--- a/awx/main/conf.py
+++ b/awx/main/conf.py
@@ -446,7 +446,9 @@ register(
 
 
 def logging_validate(serializer, attrs):
-    if not serializer.instance:
+    if not serializer.instance or \
+            not hasattr(serializer.instance, 'LOG_AGGREGATOR_HOST') or \
+            not hasattr(serializer.instance, 'LOG_AGGREGATOR_TYPE'):
         return attrs
     errors = []
     if attrs.get('LOG_AGGREGATOR_ENABLED', False):
diff --git a/awx/sso/conf.py b/awx/sso/conf.py
index f717869e7e..97648668f8 100644
--- a/awx/sso/conf.py
+++ b/awx/sso/conf.py
@@ -1089,7 +1089,9 @@ register(
 
 
 def tacacs_validate(serializer, attrs):
-    if not serializer.instance:
+    if not serializer.instance or \
+            not hasattr(serializer.instance, 'TACACSPLUS_HOST') or \
+            not hasattr(serializer.instance, 'TACACSPLUS_SECRET'):
         return attrs
     errors = []
     host = serializer.instance.TACACSPLUS_HOST
diff --git a/docs/tower_configuration.md b/docs/tower_configuration.md
index 268527a9aa..ca5fdfee8c 100644
--- a/docs/tower_configuration.md
+++ b/docs/tower_configuration.md
@@ -108,3 +108,5 @@ register_validate("category_a", validate_a)
 register_validate("category_b", validate_b)
 ...
 ```
+
+It should be noted that each validation function will be invoked in two places: when updating the category it's responsible for and when updating the general category `all`. Always keep this fact in mind and test both situations when developing new validation functions.