I had v3.x and now upgraded to 4.x but same problem - when I double click on a .bvr clip in windows explorer (win 7 64 bit home pro) it plays back in blue iris, but I get no audio. I have the audio settings correct in BI and my speaker on the laptop is on, other audio plays, just not in BI. If i convert them to mp4 i get audio, so i know it recorded audio. but why none when playing back bv4 files?