[Discuss-gnuradio] Trouble using file source

[md123]

Hello everyone,
I am using GRC to receive digital signals. I am getting perfect audio and 
perfect scopes.  I hooked up a file sink directly to the receiving device 
(RTL2832). On replaying the capture, the gui greys-out.  The gui never 
greys-out when receiving live.  I have the throttle after the file source as 
was shown in tutorials. 
Is it possible that the capture is being done incorrectly? Or is the problem 
with the replay?  What am I doing wrong?  
Thanks,
Matt
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