How can I play undf format?

Answer 1

UNDF is an undefined file. This may be because it is corrupted, or it is still in the process of being downloaded, and therefore vital information is missing. It is not a file type.

Another reason that the file is not playing, is that the media player used does not have the suitable codec for it. Try using other players (the one that does the trick when VLC says that the file is undf, is SM PLAYER)

Answer 2

undf file extension means that the type of the file you are trying to play is not defined. There are different reasons for that. One of the is just the file is damaged... Other one is the hardware/software you were using does not give proper extensions... You will have to fix it manually.

There is one more case it's when you are dealing with proprietary files which are protected... If you do not know how to decode encrypted video you just can't wath the file.

Answer 3

Video files with the extension "undf" (or "unidentifiable") must be treated with caution as they are usually found with fake files. Do not attempt to open these as they could easily corrupt the system.