I have the WDM driver disappearing as a regular event, though its regularity varies.
One situation that will cause it to disappear is if you have auto-update enabled, and MC does an update right before your machine reboots automatically (or manually) for its updates.
Other times, it will be working at night when I go to bed, but in the morning it's gone! And that's while actively streaming from VLC streaming a network station, to the MC WDM interface (system default). All I do is reinstall the same or newer version of MC and hit play on VLC and it goes with no further issue. This doesn't happen every night, but maybe 20% of the time. Most of the time I don't even need to hit play on VLC, the link just works.
For any mysterious disappearances of WDM, the simplest thing for me to do is reinstall MC over whatever version is there, and it's fixed. I have the latest or newest download handy for those cases.
BTW this odd disappearing of WDM has been going on for months. But there could be different causes for each case.
--Bill