role must not be be named like a host

local.yml

@@ -92,11 +92,11 @@
   roles:
     - nameserver
 
-- hosts: webserver
-  tags: server,webserver
+- hosts: webservers
+  tags: server,webservers
   become: true
   roles:
-    - webserver
+    - webservers
 
 - hosts: mailserver
   tags: server,mailserver
@@ -147,7 +147,7 @@
 #     - printspooler
 
 - hosts: jitsimeet
-  tags: server,jitsimeet,webserver
+  tags: server,jitsimeet,webservers
   become: true
   roles:
     - jitsimeet