But I can explain it a little. DivX has many versions. So if your encoding choice was a newer DivX than what is in the player then that message will happen.
http://en.wikipedia.org/wiki/DivX notes a lot of versions but it seems we are left holding the bag wondering which to try.
Bob
I've newly purchased dvd player LG DV642. first time I've converted one video through AVS convertor on AVI format using DIVX and XVID codec, it played perfectly but next day I've converted other video on the same format, it is not playing on DV642 and saying "UNSUPPORTED VIDEO FORMAT". Somebody can help me out on that???

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic