amyhughes wrote:but my problem is not with the beta version.
Try upgrading to the beta version. The 1.2.6 version is no longer developed or supported.
You are already using the Beta version - 1.2 does not have FFmpeg support or Libraries preferences.
Have you repaired permissions? Have you checked in Finder if /usr/local/lib/audacity is locked?
Have you set environment variables for dynamic library search which are picking up another copy of the FFmpeg library? Either set the DYLD_LIBRARY_PATH environment variable to pick up the FFmpeg library you downloaded, or remove the variable. You can adjust standard environment variables in your .profile or shell environment, or via a property list in ~/.MacOSX/environment.plist .
If the problem persists, start Audacity afresh, try to locate FFmpeg in Audacity Preferences, open Help > Show Log, and paste the contents here.