Only first few seconds of certain MKVs play. (SOLVED)

[KiyoshiSenpai]

When attempting to play certain MKV files, the thumbnails are mostly black with pixeled pink, green and grey squares; upon attempting to play these files, they show the same way, a blur of pixels. The subtitles show fine, and the audio is also fine; it plays the first 10-20 seconds and then stops and goes on to the next file without logging anything citing an error. I attempted to add the * to the "force transcoding" line under the transcode tab to make it always transcode. This did fix the video, however the videos always stop around 40 seconds and UMS moves on to the next video. Most of the videos are about 20 minutes, but I'd also tried it on a file about a minute and a half; it still only did the first few seconds.

Thanks for any assistance.

(Removed Code as problem is solved and it wouldn't let me update the subject to say "Solved" because the forum believed it looked like a spam message.)

[KiyoshiSenpai]

Solution found. Hopefully this is helpful to somebody else in the future.

Both problems appear to be related to the renderer. I determined this to be the case by testing it on a Playstation which didn't have these problems (and is what I usually stream to; I found the problem wasn't unique to MKVs, I just thought it was because these were MKVs I was trying to play to a different device than I usually stream to).

To edit your renderer if you're having a similar problem, click on the picture of your device on the main "Status" tab of UMS. Another window will pop up; click on the button that ways (whateverwhatever).conf and it should open up or ask you what to open it with; any text editor should do. I used Note++.

Pixelated Playback:
The reason it was playing heavily pixelated was because the renderer thought that it could play mkvs, as they were listed on the .conf file under
# Supported video formats:

I commented out the line for mkvs from the conf file. With that, even without forcing all files to transcode, it will transcode. The renderer I was streaming to should be able to play some mkvs but others it has trouble with, so best to just render them all. I used VLC after looking in the #Transcode# folder for ones which worked.

Only playing the first few seconds of videos:
I noticed my file sizes were all reading as "976.56kb." I did some Googling and found a thread that explained that this is because the renderer can't really know the file size of the rendered file until it's rendered and that could take several minutes. UMS is assuming that's the file size.

I changed TranscodedVideoFileSize = to -1, which then began telling me all file sizes were 1.9 mb, but everything's played just fine since.
I also put it in as 2000000000 out of curiousity and it produced a larger file size. Also worked with no problems.

At any rate, for anyone else having similar problems, I hope these help.

In summary:
Pixelated Playback:
Look in the Transcode folder for which transcoder produces the results you want and put that one at the top of the transcoder list. I used VLC. VLC usually works for anything I can play on my computer.

A. Try forcing transcoding for all file types by putting a * in the Common Transcoding settings under the transcoding tab
B. Remove or comment out (#) the file type from "Supported Video formats" in the .conf file for the device playing it back poorly.

976.56kb file sizes, only playing the first section of a video:
Open the .conf file for the device you're streaming to and change TranscodedVideoFileSize to -1, or some absurdly high number.