First right click on the Skype Icon in your system tray and change your status to "Offline" for 5 seconds and then back to "Online".
If these not helps You then Try The Following Steps:
1. First Please stop any and all running Skype Client programs on your system.
2. Then using your Windows Control Panel Add/Remove Programs uninstall Skype, when prompted to save your history, choose yes.
3. Now Using windows File Explorer "What you use to view files with" do:
%appdata%\skype
Now if you find a file called shared.xml right click on it and choose delete.
4. If you see a folder for the Skype name in question, click on it, if you see a file called Config.xml right click on it and choose delete.
5. Using the Windows file Explorer enter:
NOTE: If This is a 64 bit system, please look in the program files (x86) folder
%programfiles%
Right click on the Skype folder and choose delete.
6. Please install the normal version if you are using latest version or you can re- install the latest version also.
For more Help You can Go on This Site:
http://community.skype.com/t5/General-Discussion/Problems-with-sending-messages/td-p/159290