Had the same problem, here’s the fix:

1. Shut down Yahoo! Messenger if it is currently running.

2. From the Windows Start menu at the left bottom of your screen, click
“Run.”

3. From the input area, type regedit and press “Enter.” The registry
editor application should open.

4. On the left side, expand the HKEY_CURRENT_USER folder (or key), then
expand the Software folder under it and select “Yahoo.”

5. If there is a Webcam folder, go to the next step. If there is no
Webcam below the Yahoo folder, go to the Edit menu and click New, Key,
and type Webcam.

6. Select the Webcam folder.

7. From the Edit menu click on New, DWORD Value, and type UseVFW
without any spaces.

8. Double-click on the entry UseVFW and change the entry in Value data
to 1. Then click “OK.”

9. Exit the Registry Editor application.

Regards,
Asaccin