Hello
I'm experiencing a problem I've never had before in SHS6.
I often record music in MIDI from my keyboard, then Insert the Soft Synth "Cakewalk TTS"
to assign synth voices to different tracks for Exporting into Audio files.
Suddenly today, the soft synth will not work.
I recorded 2 MIDI tracks, then Inserted the CTTS Soft Synth and assigned the
outputs for both to the Ch 1 (Piano) sound. When I tried to play it, the play button
would not work. I press it and nothing happens.
The "Audio Engine" button is not lit, and will not light when I press it.
If I press the Panic button to reset, THEN press the Audio Engine button, it lights for
a split second and goes off.
I tried opening a project that only had audio tracks (no MIDI), and the audio played
fine (the A.E. button was lit).  While in that project, I tried adding a MIDI track,
recording a bit, then inserting the soft synth / assigning the output, and when I did,
the problem recurred. No playback, A.E. button will not turn on.
I'd appreciate any insight!
Thanks a lot.

I think I would try inserting some soft synth other than TTS -- if that works then the issue may be TTS specific.

What if you try it the "traditional" way. First insert TTS-1 and then record the MIDI. If you did not have TTS-1 running when recording the MIDI, what did you use to hear the sound (to know what you were recording)? Was the routing left for MS WAvetable or something like that?

You're not trying to use 96KHz sampling rate are you? TTS-1 doesn't work at that resolution. 

Do your older projects still work?