full reinstall with an Office update solved the issue.
Please verify the latest Office update on the PC, and reinstall the client in this way:
Procedure
1. If open, exit Microsoft Lync / Skype for Business client.
2. If open, exit Internet Explorer.
3. Open the Windows Explorer tool and navigate to the location of the Avaya Communicator for Microsoft Lync .zip file.
4. Unzip the file.
5. Double-click the Microsoft Lync SDK installation file:
• LyncSdkRedist-4.0.7577.124.msi for 2010 installations or lyncRuntime.msi for
• 2013 /Skype for Business installations, and then follow the instructions to complete the installation.
6. Run InstallLyncAddin.bat file and follow the instructions to complete the installation.
• You may receive a prompt to restart the system. If this occurs, you must reboot the machine to complete the installation.
7. Start the Lync / Skype for Business client.
8. Start Avaya Communicator for Microsoft Lync.
• From the Windows Start menu, select Programs > Avaya.
• For Lync 2010 clients, select Avaya Communicator for Microsoft Lync 2010.
• For Lync 2013 Skype for Business clients, select Avaya Communicator for Microsoft Lync 2013.
Note:
• You only need to start Avaya Communicator for Microsoft Lync after the initial Installation. For subsequent Lync Skype for Business client startups, Avaya Communicator for Microsoft Lync also starts.
9. If the Avaya Communicator for Microsoft Lync Settings window opens with the Phone tab displayed, enter your Extension number and the Password for your extension.
