The file you are trying to open is not a Cakewalk formatted file-D'OH!!!

This SUCKS!! I had been working on this song for a while now. Bed tracks WERE done. I had bought an IR pack from Red Wire (AWESOME BTW!!) I loaded a few into the Poulin LeCab2 Rev1 I noticed CPU meter was getting high 60% or so. It crashed. I tried to re open project and got above subject message. I tried to import the back up-I always copy and paste .bun file to a second drive just in case there's a cra---aw you know? It had the same error message. So I went in to the audio data folder. I tried to play .wav files from there. WMP gave me a missing codec error message?? So I opened an empty GTP3 project and imported a few .wavs I thought they would be one complete .wav-track of drums or whatever. But I found bass had gotten on to some of the drums for an example. I CAN do this over-don't want to but can. Is there any way to salvage anything? I will start putting .bun files on a flash drive as a 3rd back up option.