I included candy js in website but i am getting following error in my console window

[Surendra0451]

function f.Connection.prototype.sendIQ/h<() " - error - " TypeError: a is null Stack trace: f.unescapeNode@http://localhost/candy-2.2.0/libs.min.js:1:12397 Candy.Util</a.unescapeJid@http://localhost/candy-2.2.0/candy.min.js:1:6393 Candy.Core.Contact.prototype.getJid@http://localhost/candy-2.2.0/candy.min.js:1:23670 Candy.Core.ChatRoster.prototype.add@http://localhost/candy-2.2.0/candy.min.js:1:20665 Candy.Core.Event</a.Jabber._addRosterItem@http://localhost/candy-2.2.0/candy.min.js:1:27187 Candy.Core.Event</a.Jabber.RosterPush@http://localhost/candy-2.2.0/candy.min.js:1:27020 ._call_backs@http://localhost/candy-2.2.0/libs.min.js:3:1214 ._updateItem@http://localhost/candy-2.2.0/libs.min.js:3:2201 ._updateItems/<@http://localhost/candy-2.2.0/libs.min.js:3:1710 f.forEachChild@http://localhost/candy-2.2.0/libs.min.js:1:8462 ._updateItems@http://localhost/candy-2.2.0/libs.min.js:3:1660 ._onReceiveRosterSuccess@http://localhost/candy-2.2.0/libs.min.js:3:227 f.Connection.prototype.sendIQ/h<@http://localhost/candy-2.2.0/libs.min.js:1:19281 f.Handler.prototype.run@http://localhost/candy-2.2.0/libs.min.js:1:15817 f.Connection.prototype._dataRecv/<@http://localhost/candy-2.2.0/libs.min.js:1:22445 f.forEachChild@http://localhost/candy-2.2.0/libs.min.js:1:8462 f.Connection.prototype._dataRecv@http://localhost/candy-2.2.0/libs.min.js:1:22278 Strophe.Bosh.prototype._onRequestStateChange@http://localhost/candy-2.2.0/libs.min.js:2:6782 "a is null" libs.min.js:1:16005