DP 7.24 suddenly can't see 828x I/O

[gtrnstuff]

I have also sent this to DP, but with the holiday, maybe someone here can help sooner.
Thanks in advance for any ideas.

Finished (fortunately) an overdub project, using 828x as my interface.
Had been working fine with this setup for a few weeks.
All good. Closed DP.
Did a few other things, no OS or other software updates.
Launched DP to check another project. Tracks that were assigned to Main Out 1-2 are briefly italicized, and change to Built-In Output 1-2.
No 828x I/O in Audio assignment list.
828x shows up in System Profiler and Audio MIDI Setup, and plays audio from iTunes and Safari.
I have rebooted the Mac. Same problem. DP still can't find the 828x I/O.

[mikehalloran]

I'd shut everything down, disconnect and reconnect the interfaces. Then I'd turn the peripherals on before starting up the Mac.

[gtrnstuff]

Worth a shot but nope.
Maybe I'll go to my Time Machine and restore before the last time it worked on Friday.

[gtrnstuff]

TMB restore didn't change anything, and in fact gave me an error message: "myusername" can't be modified because it's required by OS X.
So that may be another issue to chase.

Well, I decided to try a demo of DP 9, just to see if anything would change.
Not at first.
Then the new box on the top row caught my eye, telling me clock source "internal", buffer size, etc. I clicked and clock source couldn't be changed from there.
That got me to go to Setup/ Configure Hardware Driver.
There, the 828x was visible but *not* selected, and "Built-In" was.
Easy fix, once I found it.
I have now idea what caused that to be changed.

So I quit DP 9, opened the project with my old DP 7.24, went to Setup and did the same thing.
It works now.

[Tonio]

didn't catch if you're using USB or thunderbolt? anyway try changing/use another cable, make sure sure no app napps are enabled.

[gtrnstuff]

Thanks, but I found it.
No idea how Built-in audio was selected instead of 828, but that was all it took.
I hadn't changed anything in Hardware setup in years.