Welcome to the forums.
Without you posting MediaInfo on the movie you tried to play that gave you problems it’s impossible to say for sure, but it *sounds* like you played an MKV made with a “bad” version of MKVMerge (greater than 4.0). Once you do that it will then give you the symptoms you describe (and the only way to fix it is to reset the Live as well as unplug from power for at least 10 minutes).
So first – reset your Live (with the paperclip hole in the side or through the menu) and unplug for at least 10 minutes. Then _ do not play any MKV file _ or it will do this again (you need to be sure of the file you are playing and since you’re on the road this may be difficult. Let it wait until you get back. Play files you’ve made yourself or anything other than an MKV file). When you get back home you can fix those files (using a version of MKVMerge 4.0 or earlier or later versions with header compression turned off).
If you aren’t playing MKV files then none of this applies and you have a different problem (so just ignore this message completely – in that case you might want to try playing movies off a different drive. However, I’d still reset the Live as described above).
