The selected file cannot be played, likely because it is a format Windows Media Player does not understand the file format or the needed codec is not installed.
Check if a newer version of the software is available, and if so, download and install the update.
Microsoft updated Windows Media Player frequently to include newer file format support and expand the number of codecs built in. A newer version may support the files you are attempting to use.
We recommend going to the codec vendors site rather than some random download site, so you get the latest version and ensure a quality download.
You may also find this Microsoft Codec FAQ guide useful.
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