Loaded in a project recently containing Sonnox' new Codec Toolbox plugin as well as Sonnox' Pro Codec on a stereo project that used to work. After the X3C update, I get the following dialog upon loading the project:
 
"Preset Data SampleRate/Format Clash

The Preset being loaded was created on a Stereo system at a sample rate of 44100, whcih is incompatible with this plug-in (which thinks it is a 5.1 Surround running at 44100).

If the stated plug-in configuration is incorrect, please press play, stop, and try loading the preset again.
Preset load aborted."
 
And it's true - the plugins now appear to believe they're running on a surround-sound track instead of a stereo one and there's no obvious cure. Deleting the plugs and instantiating new copies doesn't make the problem go away, either - this is a new (and not good) behavior.
 
-djh