I just upgraded to Vegas Pro 18 and Sound Forge Pro 14 and there seems to be two bugs (possibly).
1. For any video clip with it's native audio track when I click on "Open Copy in Sound Forge" I get an error message saying:
"VEGAS Pro is currently using the media file(s) so they cannot be closed. Try stopping playback, stopping recording, and any external timecode synchronization."
It does seem to replace the audio with a wav file as expected, but just doesn't open it Sound Forge. I need to close the error box and make a second effort to "Open in Sound Forge" in order to edit the new wav file. Once the audio has been replaced with a wav copy, then doing the "Open Copy..." again will work and immediately create and open a second copy as expected.
2. For a video clip with stereo audio, if I have the "Left Only" audio channel active and then click on "Open Copy in Sound Forge" (in addition to the error above) the new copy is a lower frequency by probably a couple octaves. Really weird. The frequency stays normal if the channel is changed back to stereo first.