RTL SDR and GRC3.7.8 problem: format error

Ever since I updated to GRC3.7.8 none of my RTL SDR demos will run in
GRC.
The error messages are the same: " list contains an invalid format".
Attached is the .grc file of a basic RTL Qt test flow graph authored
using
GRC3.7.8, and the .odt file with the complete error message. GRC
detects
the RTL device, and cites format errors. Are others having this
problem
with GRC3.7.8? I am anxious to resolve this problem because I have
scheduled a GRC presentation in the near future.

Regards,

John Petrich

On 08/24/2015 02:26 PM, John Petrich wrote:

Regards,

John Petrich

Did you re-build gr-osmosdr against 3.7.8? My suspicion is that the
gr-osmosdr you’re using is out-of-date with respect to the GR that is
calling it.

Also, you have a throttle block in between your hardware source, and
your Qt GUI block. Don’t do that. You never need a throttle when
you’re using
real hardware.