[JerryA]

I just registered on the forum. I logged a thread "Sound Suddenly Stops" and today, sifting through the threads I saw this one.
I'm using PT 11.3.1 and having the same issue - I'll have an audio clip playing and then the sound just stops. Meters are still registering but nothing audible.

I don't know if it's Pro Tools or my m-audio fast track pro.
Things I've tried that haven't resolved the issue...

Reinstalling old m-audio driver
Reinstalling new m-audio driver
Changing bit depth (in m-audio driver and in PT session) and sample rate
Used wart to power the fast track pro instead of bus/usb
(Ensured the usb is connected to usb2)
Tried connecting to different USB ports on the back of the PC tower

Control panel
Made sure fast track pro is the default sound card

Pro Tools
Quitting PT and reopening session
Resetting outputs
Resetting sample rate of clip (sometimes a short term fix)
Right clicking on PT icon and in compatibility, changing OS to another OS (this sometimes has worked)

Things I haven't tried but probably will today
Deleting master track (I saw that tip in this thread)
Swapping the USB cable for a new one
Loading the fast track pro into a catapult and firing it out the window

I read a response from Avid to someone that was frustrated with this issue and some of the remedies included
Make sure speakers are connected and switched on
Make sure external sound card is connected and switched on
Make sure the clip is not muted

Maybe fair enough if this was isolated and the person was an obvious newbie. But this issue appears to be pretty systemic, and not isolated to a specific release, or sound card. For me, my Avid setup just doesn't reliably do what it is supposed to do, even though I paid top dollar for it.

I'm spending more time trying to sort my PT chain than I am making music. If making music was my livelihood, I'm wondering how long would it take me to go bankrupt.