Openfire 3.8.2 is pretty old. Between 3.8.2 and 4.6.3, a lot of improvements were made, some of which include changes to the way authentication occurs (which is based on SASL). Additionally, some of the details of how authentication occurs depends on the version of Java that is being used by Openfire (which might have gotten an update too, when Openfire was updated).
It seems that whatever library that is used by your project does not work well with the more modern implementation of the authentication mechanisms in Openfire. Apart from disabling authentication mechanisms in Openfire (or making available the non-SASL mechanism through the correspondingly named plugin, which is not recommended), this seems to be an issue that needs to be addressed by the XMPP library used in your project.