[op25-dev] Is this configuration supposed to work?

GNURadio installed with Pybombs OP25 installed with pybombs Versions are: gnuradio-config-info v3.7.6.1-128-g8a3ad1a5 uhd_003.008.002-131-gb850dfb5 ubuntu 14.04 LTS OP25 blocks show up in the list of blocks available for use in GNURadio Companion and decoder_bf,fsk4_demod_ff, fsk4_slicer_fb and pcap_source_b and gardner_costas_cc seem to add to the flowgraph. decoder_ff, vocoder and p25_frame_assembler cause the flowgraph to go blank with a final error in the terminal window of AttributeError: 'Block' object has no attribute 'horizontal_label'. Have done some quick searching, but have been unable to determine if this set of versions is supposed to work and what the problem may be if they are. If someone can comment (or point to a link that comments) on whether this configuration is supposed to operate it would be much appreciated. Thanks, LVDJ