Mkv extract... worked once.. now flawed!

[Mushmello]

Please forgive me if this has been covered somewhere... Ive done some searching (might not be hitting the right topics)

Im trying to extract an .MKV using MKVextractGUI and am experiencing issues. I recently extracted it and had no problems i was able to pull out all the subtitles, audio and video info. After some conversions and whatnot i was able to get a clean running video burnt to DVD but had issues getting the .AC3 audio working on the DVD. For whatever insane reason i figured the extraction might not have worked properly and decided to do the entire process from scratch. I deleted everything except the .MKV file and figured redoing everything might somehow fix this issue. Now everytime i try to extract the .MKV my computer experiences a massive CPU increase (which never happened before) also the .MKV info (audio,video,subtitle) is not shown anymore only "chapters" is shown. Before the extraction process was reletivly quick... now the extract button isn't even highlighted.. have I damaged the .MKV? or what might be the issue here? SORRY for the insane long post.. trying to make sure all the info is here.. thanks so much for your time on this one!

[45tripp]

i don't know about cpu load but mkvextract often fails to recognize the streams.
keep reloading.
there's also a reset option under file you might want to click a few times.

[celtic_druid]

Try it without the GUI.