My built in webcam has stopped working on Skype following an update. Does this mean my macbook air has blocked videochat on skype? How can I fix this problem?

See this thread:

https://discussions.apple.com/thread/5306216?tstart=0

FIX: 😊

1. 1. You need Time Machine
2. 2. Go to folder /Library/CoreMediaIO/Plug-Ins/DAL/
3. 3. Copy AppleCamera.plugin to good place (usb memory stick is the best place).
4. 4. Go to Time machine in date that skype work fine.
5. 5. Change AppleCamera.plugin with file from Time Machine
6. 6. Restart system, Now skype need to work with camera.

If that doesnt pass,

Suggest looking here, much success has been found:

http://community.skype.com/t5/Mac/OS-X-10-8-5-broke-Video-on-MacBook-Air/td-p/18 91729/page/4

see the first link posted.

nobody has encountered a problem on same.

Actually that link does explain the "relevance to my problem"

This solution has worked for countless folks. However as you wish. 😊

MacBook Air (Mid 2013): FaceTime HD Camera might not work after OS X 10.8.5 update