Firefox can not be open after you install it on MaC

After you download and install Firefox on your Mac you may see the error message, "Firefox.app" can't be opened because the identity of the developer cannot be confirmed when you try to open it.

Apple has made a security change to Mac OS X 10.9.5 which may cause this error and block you from using Firefox. Here are some steps you can take if this happens:

1. Hold down the Control key while clicking on the Firefox icon in the Dock or on the Firefox application file in a Finder window.
2. Click Open in the context menu.
3. Click Open in the following dialog window.