Every WMV that i threw at it so far, will crash the program. After indexing, it always comes back with:
Codec
Internal error finding codec 0x33564d57
And then it builds crash info and closes. admlog.txt is attached.
Unfortunately I can't give access to the videos in question, because they are inappropriate.
Anyway, I've tried three of them, all from different sources as far as I can tell, but all of them* are 1080p WMV's and all do exactly the same thing.
That's on Windows 7 x64, Avidemux 2.6.4. 32-bits.
/edit
* actually one is 720p. So I guess resolution is not the culprit.
/edit2
All three, the ones I tried, import into Avidemux 2.5.6 without a hitch.