Skype for business… it used to be “acceptable”. These days it’s the notepad of the conferencing world. Skype has recently broken compatibility with Virtual cameras with the new versions of MAC OS, so here’s the trick (based on this forum reply):

;TLDR:

sudo codesign --remove-signature /Applications/Skype\ for\ Business.app/

The Long Version:

On Mac OS X 1. Close Skype App 2. Open Terminal (if you don't have XCode Installed, do items 3 and 4)

3. run

Xcode-select --install 

4. install and update Xcode

Most important part:

5. run

sudo codesign --remove-signature /Applications/Skype\ for\ Business.app/

When Done:

• ou will lose your Skype settings.

• when Skype is started the first time you need to enter your admin password and hit "always permit".

• After that you are able to access your virtual cameras again.