Unable sent message to Yahoo

We are able successfully sign into yahoo but we are uable to sent message to yahoo ids.

We are not getting any error message…Pls help
images.rar.zip (813783 Bytes)

The IM Gateway plugin is no longer maintained or support. You must install the replacement plugin Kraken not found on this site. It can be found at: http://kraken.blathersource.org/

Support for that plugin is provided at that site as well.