hi i'm fairly new to video editing and have come across an extremely annoying problem shortly after downloading AVS video editor.

I imported about 40 uncompressed short AVI files from fraps and began to make a short clip of it, accompanied by several audio and video effect tracks. it was going great, i found the program extremely easy to use but with more options and detail than windows movie maker.
However when i saved and exited and went back in a few hours later i tried to play my unfinished clip, it was only a blank black screen, still with audio. i downloaded K-lite codec pack full as someone reccomended to me and that hasn't fixed the problem.
can anyone please help? i've made 3 new projects, spending 5+ hours on each but they all have the same problem