That means your ECU doesn't communicate with your RT6 any more..I'm afraid something went wrong inside your RT6 unit(some chip burned so the coding can't contiune).
I don't know what to say,try some electric resets like remove radio fuse or remove battery,but as i've said at the beginning it might be a software/hardware problem.
can you tell us more about this problem? have you solved it ? I have the same problem on my car but only on USB audio playback: I have a folder with about 300 songs and sometimes the music sounds like I'm listening from a broken CD, then the unit restarts and I need to remove the USB from dock and plug it back in to solve it. I am afraid not to have some sort of damage on the unit.
Had the same problems from day 1 i bought the car. Partialy solved it with buying faster usb but the main problem is when i shuffle music from usb. So if i shuffle some folder it works but if I shuffle others the RT6 goes into loop restart until i unplug usb. Solution: No shuffle no restarts.
To explain in more detail different scenarios.
1.) I had pluged in my usb and was playing music in shufle mode. After a while it restarted and went into loop as you said at logo and it continued to restart at logo untill i unpluged the usb.
2.) I am playin the music whole day without problems but in shuffle mode. Next day in the morning when i started the car it immediately went into loop because previous day i was normaly listening to music in shuffle. So as i understand the RT6 couldnt resume playing music next morning so it just went into loop at start and cuntinue to restart at logo until i unpluged usb.
So as i said some folders caused this loop some didnt. I now just not use shuffle on music that i know it will cause the loop and it helped to buy faster usb to some music.
I have a DS5 with RT6 After one week my display went black or flickered
The reason was my CD player It was totaly dead..After i got a new CD player installed everything was ok.
I was then told not to have a cd in the player while i used usb. That could make problems.
Yust wanted to tell you what they said
Have a nice day