Please try again following EXACTLY the instructions that I gave you in my post #5 above! Also make sure that there is a valid MLV file called IMG_2138.MLV on your Desktop and it was generated in your Canon camera if you want MLVApp to open it. Your file name looks strange to me. If generated by your camera, it should look like M21-2138.MLV or similar. Did you rename it? Just record a short MLV video file in your camera, move it to your desktop and try again.
If you use the Transcode and Import option to pack your stills .CR2 files into MLV files for opening in MLVApp, just wait for the transcoding process to finish. This can take quite a while if you have lots of CR2 files in your directory! If it still does not work, please use the 32-bit RAW2MLV package with the 64-bit version of MLVApp.
I have exactly the same files in my MLVApp directory as you. Just checked and it works perfectly here!