Unable to login to Openfire with Spark Client

We have been using Spark client with Openfire (3.9.3) for few years now. Recently there were some changes done by our IT and Infra team on firewall and DMZ post which we are noticing that users are unable to login when they are connected within Domain. Once outside the domain (or connecting from internet), the same use is able to connect from the same system using same credentials. Need help to figure out how to debug this. we use MicroSoft AD ldap to authenticate users. ldap is hosted on a separate server which is accessible from the openfire server.

What Spark version and what error it gives?

Spark 2.6.3.12555

Error while trying to log-in from corporate domain - “Login error” - Invalid username or password.

If we use datacard (connect from outside corporate domain), with same credentials, login works perfectly fine.

Well, that’s an old version and it was giving this same error for various reasons, so it is no very helpful. You can try checking the logs at C:\Users\username\AppData\Roaming\Spark\logs and maybe you’ll find something more useful.

I don’t quite understand the last part, what do you mean by datacard and what exactly mean domain in your case. Is it only to indicate you are ourside of your internal LAN or do you put different domain name into Spark. If it was after the change of your IT staff, maybe it would be easier to investigate with them which change is causing this, so it would be easier to understand what is happening.

You can also try installing Spark 2.8.3 on one endpoint to get a more informative error.