javax.security.sasl.SaslException: PLAIN authentication failed

Dear Expert,

We are using openfire extensively past years with version 4.6.6 and now we tried upgrading to latest ver 4.7.3.
Unfortunately we are getting below error while login in.
javax.security.sasl.SaslException: PLAIN authentication failed

We are trying in our custom android application.

@guus @ kindly advise .

Thank you
Mat