MeGUI hangs on pre-processing after extracting audio tracks

[CasanovaFly]

I use MeGUI to convert MKV's with DTS/AC3 to AAC sound in the MKV. I use the one click encoder and leave the video unconverted.

More often than not, it will begin by extracting the audio track successfully and will then proceed to pre-processing, where it will hang indefinitely. It doesn't go anywhere. It's been left for hours with no results. Normally it pre-processes for a couple seconds max, but not in this case.

Any ideas what the problem is? I've had quite a few successful runs at this, so I can't nail down what the problem is exactly. As of right now it just seems to be random, but then I don't know much about MeGUI as I'm new.

Any help is greatly appreciated.

[CasanovaFly]

Update: it seems that AC3 and DTS files don't work equally when it's the same file. I had an MKV with DTS that I converted to AC3 using Popcorn, and it didn't work either. Makes me think it's something to do with something inside the file.

[CasanovaFly]

Problem solved.

It was apparently other files in the container giving MeGUI problems. Could have been having more than one audio file, but if I use mkvmerge to remove everything but the video and the audio in question, remux that and try to convert it works fine.