The .wmv version loads fully.
I'd already found this by testing a .wmv file almost identical to one of the many .avi files that won't load.
However, for example, the .avi test file that I sent is 9.42Gb, and the .wmv version that you have returned is only 780Mb,
and I'm concerned about loss of quality, clarity, etc doing this. I'd rather edit the original file and convert at the end,
or when uploading as another format in order to retain the quality of the original file.