feat: Add warning for self-hosted installations that don't auth auth method configured

server/pages/components/SigninButtons.js

@@ -4,6 +4,7 @@ import styled from 'styled-components';
 import Button from './Button';
 import { signin } from '../../../shared/utils/routeHelpers';
 import Flex from '../../../shared/components/Flex';
+import Notice from '../../../shared/components/Notice';
 import GoogleLogo from '../../../shared/components/GoogleLogo';
 import SlackLogo from '../../../shared/components/SlackLogo';
 import breakpoint from 'styled-components-breakpoint';
@@ -21,6 +22,13 @@ const SigninButtons = ({
 }: Props) => {
   return (
     <Wrapper>
+      {!slackSigninEnabled &&
+        !googleSigninEnabled && (
+          <Notice>
+            Neither Slack or Google sign in is enabled. You must configure at
+            least one authentication method to sign in to Outline.
+          </Notice>
+        )}
       {slackSigninEnabled && (
         <Column column>
           <Button href={signin('slack')}>