ERROR in login ANTAMEDIA INTERNET CAFFE v. 5.4.0

Hi All,

I am refering to one of my issue I am facing with ANTAMEDIA INTERNET CAFFE v. 5.4.0.
If other users can share the workaround its going to be big help. I want to thank them in advance.
Here is my problem, I was using ANTAMEDIA INTERNET CAFFE v. 5.4.0 for few days and configure few clients machine connected with server without any problem.
After few days I encounter with an issue because of which I can not login to Server. In the login dailog box it says ERROR in place of User ID.

Does any body has encounter the similar problem, if yes please share the workaround with me, I have to get the configuration backed up.

Thanks again.