8.5.3 Project in X1 -- No Playback

So far I haven't had too many problems with X1 but something came up tonight that I'm wondering about.

I have an old 8.5.3 project that I opened up in X1 and it won't play.  Meters are bouncing like normal--even the master buss and the "output" buss are bouncing but nothing is getting to the amp (or presumably the interface).

I have opened many 8.5.3 projects without a hitch before this.

I have a Focusrite Saffire Pro 40 and a Focusrite OctoPre MkII ... they're working fine (other projects have no problems).  I just used all 16 inputs on a session Thursday.  One thing to note is that the project was recorded on a couple of PreSonus Firepods but I have a ton of other projects that were recorded on the Firepods that open and play just fine.

I'm running XP SP3 (32bit).  4GB RAM.

One thing I've noticed is that during normal operation the Saffire has a green light marked "Linked" that is lit up.  However, when I open this problem project the linked light goes off.  If I open another project after the problem project the linked light comes on and the project plays back fine.  If I then open the problem project again the light goes off and I get no sound.

I'm running the latest drivers.  I've tried changing latency.  I've tried changing back and forth between ASIO and WDM drivers.  I've rebooted.  I've turned on/off the interfaces.  The interfaces are linked correctly with each other.

I'm hoping that I am just over-looking something obvious and hopefully you guys can point it out or at least throw some suggestions my way on how to troubleshoot this.

Sorry about the confusion and delay.  I was away over the weekend.  It does indeed say Locked ... it's tiny print and my studio is dim.  It is not illuminated for this project though.  I'll see if I can figure out where I can activate "sync" for that project.