Openfire User login logs

Hi I have a install of openfire on Ubuntu server and would like to know which file logs user access under /opt/openfire/logs/

We have one user that is not able to login and I would like to see if the openfire logs can give me some more information about this issue.

Errors are usually stored in error.log, though you can also check warn.log too. There is no dedicated log for users login.