MKV file format is multimedia data container extension. It is also known as Matroska Multimedia Container file.
It was created to store unlimited number of audio, subtitles and video files in one single MKV file. It is considered as a universal format for storing movies, TV shows and other multimedia data. It is an open standard file format. It can also contain other data related to the video data including chapter points and multilingual subtitles along with metadata which can include cover art, description, ratings and other information. The video is encoded according to VP8 standard and audio is encoded in Vorbis audio format.
In addition to the problem described above, i.e. the lack of the appropriate application to support the .MKV file, there may be several reasons that cause problems with opening and operation of the data format:
A quite common problem is the lack of application in the appropriate version. Even if you have an application, with the help of which you should open the .MKV file, you may have a problem with it because of its version. Perhaps in previous versions the application has not yet supported the .MKV file, so download the update and check again.
If you have already installed the appropriate application, and it is the correct version, the file may not open correctly, because the operating system does not have information that this program supports the file. So you need to "show" which program the computer should use. To do this:
It also happens that the file you want to open is corrupt and therefore there is no such possibility. In this situation, you should find its different version, or ask a person from whom you got, to send it again. You can also try to find more informations about this file extension here.