[BUG] crash when adding to queue

[shijan]

Earlier few times i got same (i guess same) "error telling the mkvmerge version is unknown." when replaced with MKVToolNix.app. Error happened in any scenario when i used MKV input or output container. So from some time i start to use mkvextract, mkvinfo, mkvmerge to avoid this problem. To be honest it was long time ago, so maybe it was just my mistake and i forgot to clean up some old preferences... Anyway i always used those separate files due less size than MKVToolNix.app and have no any problems anymore.