Symptoms
A user cannot use the Alt Gr key together with a character key to type a special character in a Microsoft Lync 2010 Group Chat client window.
Note The Alt Gr key is a modifier key on some keyboards, such as German, Danish, Finnish, and Hungarian. The key is used to type special characters such as €, @, £ and $.Cause
This issue occurs because the Lync 2010 Group Chat client does not support this functionality.
Resolution
To resolve this issue, install the following cumulative update:
2636065 Description of the cumulative update for Lync 2010 Group Chat client: November 2011