Aria Operations 8.18.x users logging in using vIDM see the error "An error occurred during OAuth2 operation"

Products

• VMware Aria Suite

Issue/Introduction

• The Aria Operations cluster is behind a load balancer
• Users see the following error after selecting the vIDM authentication source and clicking "Redirect" during login:
  
  An error occurred during OAuth2 operation. Please contact your administrator to resolve the issue.

{ "error": "invalid_request", "error_description": "Must provie a matching redirect uir."}
  
  
• The Identity Manager Service logs show messages similar to:
  
  com.vmware.horizon.service.filter.oauth2.OAuth2AuthorizeFilter - OAuth2AuthorizeFilter: wrong redirect uri

Environment

• VMware Identity Manager 3.3.7
• Aria Operations 8.18.x

Resolution

1. In a Web browser, navigate to the IP address or fully qualified domain name of the primary node.
2. Log in with the local admin account
3. Navigate to Global Settings > System Settings > System access URL and enter https://<FQDN of the load balancer VIP>
4. Navigate to Control Panel > Authentication Sources.
5. Edit the VMware Identity Manager authentication source. 
6. Enter the Username and Password for the VMware Identity Manager deployment.
7. Enter the FQDN of the load balancer VIP for the Redirect FQDN/IP and then click Test.
8. After the test succeeds, click OK.
9. Click the checkbox next to "Accept this Certificate" in the Review and Accept Certificate prompt. Click OK.
10. Log out of the Aria Operations UI. At the login prompt, select your VMware Identity Manager authentication source from the drop-down menu.
11. Click Redirect. You should be redirected to login with your VMware Identity Manager credentials. 
12. Enter your credentials and click Sign In. You should be logged into Aria Operations.