# Help **URL:** https://help.mkvtoolnix.download/c/help/4.md [Latest](https://help.mkvtoolnix.download/latest.md) · [Categories](https://help.mkvtoolnix.download/categories.md) · [Tags](https://help.mkvtoolnix.download/tags.md) --- ## [macOS 27 Issue - Checkboxes Missing in Codec Column](https://help.mkvtoolnix.download/t/macos-27-issue-checkboxes-missing-in-codec-column/1600)
**Author:** [@corticalcode](https://help.mkvtoolnix.download/u/corticalcode)\ **Replies:** 1\ **Last updated:** [October 26, 2026, 12:57am UTC](https://help.mkvtoolnix.download/t/macos-27-issue-checkboxes-missing-in-codec-column/1600 "2026-10-26T00:57:18Z")
Heads-up for Mac users: after updating to macOS 27, the checkboxes in MKVToolNix GUI are invisible. You can still check and uncheck each row but without visual confirmation. I can reproduce it on macOS 27 with MKVToolNix… --- ## [Welcome to MKVToolNix' support community!](https://help.mkvtoolnix.download/t/welcome-to-mkvtoolnix-support-community/7)
**Author:** [@system](https://help.mkvtoolnix.download/u/system)\ **Replies:** 0\ **Last updated:** [June 14, 2023, 1:14pm UTC](https://help.mkvtoolnix.download/t/welcome-to-mkvtoolnix-support-community/7 "2023-06-14T13:14:31Z")
Need help with something? Want to suggest a new feature? Ask for insight how MKVToolNix works? Confused about parts of the Matroska specification? All of that is very much on-topic in this forum. It’s a place to discuss… --- ## [Desynchronizatation video and audio](https://help.mkvtoolnix.download/t/desynchronizatation-video-and-audio/1616)
**Author:** [@dav](https://help.mkvtoolnix.download/u/dav)\ **Replies:** 0\ **Last updated:** [November 7, 2026, 9:13am UTC](https://help.mkvtoolnix.download/t/desynchronizatation-video-and-audio/1616 "2026-11-07T09:13:36Z")
Hello, A little loss of data stream in playing a ts file provoks an offset between video and audio in mkv file. Is there a way to avoid this ? Thanks for your help. --- ## [Changing aspect ratio and cropping only stretches the video image](https://help.mkvtoolnix.download/t/changing-aspect-ratio-and-cropping-only-stretches-the-video-image/1610)
**Author:** [@noxxious](https://help.mkvtoolnix.download/u/noxxious)\ **Replies:** 1\ **Last updated:** [November 6, 2026, 12:53pm UTC](https://help.mkvtoolnix.download/t/changing-aspect-ratio-and-cropping-only-stretches-the-video-image/1610 "2026-11-06T12:53:14Z")
I’m trying to change the aspect ratio of a video from 2.39:1 to 16:9, which should easily be accomplished by cropping out the reduntant width off the video. I’ve tried several different ways, but nothing seems to work. … --- ## [Delete subtitles in bulk by format](https://help.mkvtoolnix.download/t/delete-subtitles-in-bulk-by-format/1614)
**Author:** [@suncrush3r85](https://help.mkvtoolnix.download/u/suncrush3r85)\ **Replies:** 0\ **Last updated:** [November 2, 2026, 11:37pm UTC](https://help.mkvtoolnix.download/t/delete-subtitles-in-bulk-by-format/1614 "2026-11-02T23:37:57Z")
have a series that have 3 different subtitles in english. ASS,SRT and HDMV PGS. Is there a way to delete subtitles by codec or format in bulk? --- ## [Audio offset not applying?](https://help.mkvtoolnix.download/t/audio-offset-not-applying/1613)
**Author:** [@AntennaAngel](https://help.mkvtoolnix.download/u/AntennaAngel)\ **Replies:** 2\ **Last updated:** [October 30, 2026, 1:35pm UTC](https://help.mkvtoolnix.download/t/audio-offset-not-applying/1613 "2026-10-30T13:35:19Z")
First post! I’ve used mkvtoolnix in combination with programs like SubtitleEdit to identify the frame/audio positioning for remuxing many times successfully but for some reason it isn’t working now. It’s been a while sin… --- ## [Fast Forward on H265 MKV files](https://help.mkvtoolnix.download/t/fast-forward-on-h265-mkv-files/1612)
**Author:** [@aspx1981](https://help.mkvtoolnix.download/u/aspx1981)\ **Replies:** 0\ **Last updated:** [October 28, 2026, 9:16am UTC](https://help.mkvtoolnix.download/t/fast-forward-on-h265-mkv-files/1612 "2026-10-28T09:16:09Z")
Hello, I have FF/RW issues on some downloaded MKV files. I read I need to run: for f in \*.mkv ; do /usr/bin/mkvmerge -o “${f%.mkv}\_i.mkv” “$f” ; done or for f in \*.mkv ; do /usr/bin/mkvmerge --engage all\_i\_slices\_ar… --- ## [Old version mkv toolnix](https://help.mkvtoolnix.download/t/old-version-mkv-toolnix/1609)
**Author:** [@Daniel1](https://help.mkvtoolnix.download/u/Daniel1)\ **Replies:** 8\ **Last updated:** [October 25, 2026, 6:36pm UTC](https://help.mkvtoolnix.download/t/old-version-mkv-toolnix/1609 "2026-10-25T18:36:09Z")
Hello, I’ve updated MKVToolNix, but I would really like to go back to an older version from a few years ago. Where can I find that installation file? --- ## [MKVCleaver dont work](https://help.mkvtoolnix.download/t/mkvcleaver-dont-work/1611)
**Author:** [@Daniel1](https://help.mkvtoolnix.download/u/Daniel1)\ **Replies:** 2\ **Last updated:** [October 25, 2026, 6:11pm UTC](https://help.mkvtoolnix.download/t/mkvcleaver-dont-work/1611 "2026-10-25T18:11:50Z")
ik heb MKVCleaver 0.8.0.2. bij het opstarten zegt hij dat mkvextract.exe out of date is. Waarom is dit nodig? ik heb MKVCleaver en MKV toolnix altijd apart afzonderlijk gebruikt en hadden niks met elkaar te maken. MKV … --- ## [No Check for video and audio](https://help.mkvtoolnix.download/t/no-check-for-video-and-audio/1608)
**Author:** [@Blitzen](https://help.mkvtoolnix.download/u/Blitzen)\ **Replies:** 2\ **Last updated:** [October 21, 2026, 8:18pm UTC](https://help.mkvtoolnix.download/t/no-check-for-video-and-audio/1608 "2026-10-21T20:18:31Z")
Hi Have newest prog I right cliched something with too much delicious homemade wine in me and now the video and audio does not have automatic check marks. Everything else does. If it were the reverse I would be happier… --- ## [NIX speed during subtitle addition](https://help.mkvtoolnix.download/t/nix-speed-during-subtitle-addition/1607)
**Author:** [@VMac](https://help.mkvtoolnix.download/u/VMac)\ **Replies:** 0\ **Last updated:** [October 21, 2026, 3:43am UTC](https://help.mkvtoolnix.download/t/nix-speed-during-subtitle-addition/1607 "2026-10-21T03:43:44Z")
Greetings. Just an observation, I think. The time to imbed subtitles seems to have increased significantly. Is just me or has something happened? What a great programme, thanks Vic --- ## [Quitar un idioma a varios .mkv a la vez](https://help.mkvtoolnix.download/t/quitar-un-idioma-a-varios-mkv-a-la-vez/1605)
**Author:** [@JAVICA](https://help.mkvtoolnix.download/u/JAVICA)\ **Replies:** 0\ **Last updated:** [October 14, 2026, 4:24pm UTC](https://help.mkvtoolnix.download/t/quitar-un-idioma-a-varios-mkv-a-la-vez/1605 "2026-10-14T16:24:10Z")
Quito sin problemas una pista de idioma concreto de un .mkv. Pero soy incapaz de hacerlo masivamente, por ejemplo, con 10 capítulos. No se de que forma hacerlo. Si pongo varios capítulos , crea un único archivo de salida… --- ## [Chapters when merging mkv files](https://help.mkvtoolnix.download/t/chapters-when-merging-mkv-files/1604)
**Author:** [@depechefan](https://help.mkvtoolnix.download/u/depechefan)\ **Replies:** 3\ **Last updated:** [October 12, 2026, 1:37pm UTC](https://help.mkvtoolnix.download/t/chapters-when-merging-mkv-files/1604 "2026-10-12T13:37:59Z")
Hi, I have 2 mkv files that I want to merge into one and add a chapter so I can directly access the contents of the second file. The first file is a music file with 8 tracks and the second one only contains one track. I… --- ## [MKVToolNix only in system HD](https://help.mkvtoolnix.download/t/mkvtoolnix-only-in-system-hd/1602)
**Author:** [@sturmtruppenb](https://help.mkvtoolnix.download/u/sturmtruppenb)\ **Replies:** 0\ **Last updated:** [October 10, 2026, 12:57pm UTC](https://help.mkvtoolnix.download/t/mkvtoolnix-only-in-system-hd/1602 "2026-10-10T12:57:43Z")
Hi, Could someone please tell me why, if I install MKVToolNix on any HD or in any folder, it doesn’t work and gives me the error “file not recognized. error 2”? Yet, if I install it in the system drive’s Program Files f… --- ## [Regression: MKVToolNix v99/v100 crashes on startup with ASUS Strix Soar driver (v98 works)](https://help.mkvtoolnix.download/t/regression-mkvtoolnix-v99-v100-crashes-on-startup-with-asus-strix-soar-driver-v98-works/1582)
**Author:** [@GreenEagles](https://help.mkvtoolnix.download/u/GreenEagles)\ **Replies:** 7\ **Last updated:** [October 8, 2026, 12:14pm UTC](https://help.mkvtoolnix.download/t/regression-mkvtoolnix-v99-v100-crashes-on-startup-with-asus-strix-soar-driver-v98-works/1582 "2026-10-08T12:14:09Z")
Hello, I would like to report what appears to be a reproducible regression between MKVToolNix v98 and v99. System Windows 11 x64 (same Windows installation for all tests) ASUS Strix Soar PCIe sound card ASUS St… --- ## [Remux Video Audio with Time Stretch](https://help.mkvtoolnix.download/t/remux-video-audio-with-time-stretch/1601)
**Author:** [@shubhamgarg2kxx](https://help.mkvtoolnix.download/u/shubhamgarg2kxx)\ **Replies:** 0\ **Last updated:** [October 6, 2026, 7:05am UTC](https://help.mkvtoolnix.download/t/remux-video-audio-with-time-stretch/1601 "2026-10-06T07:05:29Z")
I have seen previous posts on the same topics and it hasnt helped me. I have a video 1 which is a higher quality video with an english sountrack. I have a video 2 which is a lower quality video with a hindi soundtrack … --- ## [Header Editor Removes Duration Information](https://help.mkvtoolnix.download/t/header-editor-removes-duration-information/1593)
**Author:** [@Andor](https://help.mkvtoolnix.download/u/Andor)\ **Replies:** 2\ **Last updated:** [September 20, 2026, 1:49pm UTC](https://help.mkvtoolnix.download/t/header-editor-removes-duration-information/1593 "2026-09-20T13:49:16Z")
Ver 100.0 I just noticed the header editor clears the Details information you normally see when you right-click a file and select Properties. (Widows 11). This deletes the Length (duration) info that shows up in file di… --- ## [Two titles appearing on a file](https://help.mkvtoolnix.download/t/two-titles-appearing-on-a-file/1599)
**Author:** [@PrimalWarriorDB](https://help.mkvtoolnix.download/u/PrimalWarriorDB)\ **Replies:** 5\ **Last updated:** [September 16, 2026, 12:10pm UTC](https://help.mkvtoolnix.download/t/two-titles-appearing-on-a-file/1599 "2026-09-16T12:10:21Z")
So I’ve been messing around with a video and out of nowhere I’ve noticed it has now two titles, the old one and a new one I’ve given it. I have tried using the header editor to edit the title but the old title always app… --- ## [Multiplexer imports name starting with version 100](https://help.mkvtoolnix.download/t/multiplexer-imports-name-starting-with-version-100/1598)
**Author:** [@Sleepy](https://help.mkvtoolnix.download/u/Sleepy)\ **Replies:** 2\ **Last updated:** [September 15, 2026, 9:00am UTC](https://help.mkvtoolnix.download/t/multiplexer-imports-name-starting-with-version-100/1598 "2026-09-15T09:00:29Z")
Hi I frequently use MKVToolNix GUI to remove track names. Up to version 99, the name wasn’t imported when I copied files into the multiplexer—which suited me perfectly. From version 100 onwards, the name is included, an… --- ## [\`Execute a program\` not receiving the correct data](https://help.mkvtoolnix.download/t/execute-a-program-not-receiving-the-correct-data/1596)
**Author:** [@wontellu](https://help.mkvtoolnix.download/u/wontellu)\ **Replies:** 3\ **Last updated:** [September 5, 2026, 12:55pm UTC](https://help.mkvtoolnix.download/t/execute-a-program-not-receiving-the-correct-data/1596 "2026-09-05T12:55:44Z")
Hi, I’ve been using custom actions of the Execute a program type and it has been working flawlessly except for these last versions. This is one of the commands I execute: 'C:\\windows\\myapp.exe' '\ **Author:** [@nick](https://help.mkvtoolnix.download/u/nick)\ **Replies:** 4\ **Last updated:** [September 4, 2026, 10:29pm UTC](https://help.mkvtoolnix.download/t/error-using-command-line-to-extract-sub-idx-files-from-a-dvdsub-track-in-macos/1595 "2026-09-04T22:29:54Z") I tried to run the attached CLI code to get the sub and idx files from a mkv movie file in MacOS 26, and it gave me the error message “Error: Unrecognized command line option ‘0:2’.” Does anyone know how to fix this so … --- ## [Question about license](https://help.mkvtoolnix.download/t/question-about-license/1597)
**Author:** [@Jlw111](https://help.mkvtoolnix.download/u/Jlw111)\ **Replies:** 4\ **Last updated:** [September 3, 2026, 1:32pm UTC](https://help.mkvtoolnix.download/t/question-about-license/1597 "2026-09-03T13:32:26Z")
Can MKVToolNix be licensed under GPLv3? In other words, is its license “GPL-2.0-only” or “GPL-2.0-or-later”? I was looking into integrating it into a GPLv3 project I’m working on, and I know that I can’t add any GPL-2.0… --- ## [Problems with MacOS and OCLP](https://help.mkvtoolnix.download/t/problems-with-macos-and-oclp/1495)
**Author:** [@zerozenit](https://help.mkvtoolnix.download/u/zerozenit)\ **Replies:** 2\ **Last updated:** [August 31, 2026, 6:34am UTC](https://help.mkvtoolnix.download/t/problems-with-macos-and-oclp/1495 "2026-08-31T06:34:22Z")
Hi everyone, I’m using an older Intel Mac with OpenCore Legacy Patcher and MacOS Sonoma 14.8.2. All versions of MKVToolNix GUI have always worked up to v93.0, but later versions don’t work because adding a file always gi… --- ## [Trying to merge 2 MKV files- fails immediately](https://help.mkvtoolnix.download/t/trying-to-merge-2-mkv-files-fails-immediately/1312)
**Author:** [@cappy2112](https://help.mkvtoolnix.download/u/cappy2112)\ **Replies:** 10\ **Last updated:** [August 30, 2026, 6:28pm UTC](https://help.mkvtoolnix.download/t/trying-to-merge-2-mkv-files-fails-immediately/1312 "2026-08-30T18:28:15Z")
Hi I’m running v91.0 on Windows 11 Pro. I’ve successfully merged 2 MKV files that I’ve ripped from DVDs, but am new to “merging MKVs” in general. Now, I’m trying to merge a 3-part documentary that I’ve ripped, but not… --- ## [Create a Music Album with MKVToolNix](https://help.mkvtoolnix.download/t/create-a-music-album-with-mkvtoolnix/1592)
**Author:** [@soundguy](https://help.mkvtoolnix.download/u/soundguy)\ **Replies:** 5\ **Last updated:** [August 27, 2026, 2:23pm UTC](https://help.mkvtoolnix.download/t/create-a-music-album-with-mkvtoolnix/1592 "2026-08-27T14:23:08Z")
Hi. My aim is to create a Dolby TrueHD version of a music album, using a MKV container. My input files are MLP files created with the Dolby Media Encoder from my original Dolby Atmos Master files. I have actually manage… --- ## [Apple Silicon: retirement of Rosetta 2](https://help.mkvtoolnix.download/t/apple-silicon-retirement-of-rosetta-2/1371)
**Author:** [@dark\_clefable](https://help.mkvtoolnix.download/u/dark_clefable)\ **Replies:** 59\ **Last updated:** [August 16, 2026, 7:54pm UTC](https://help.mkvtoolnix.download/t/apple-silicon-retirement-of-rosetta-2/1371 "2026-08-16T19:54:43Z")
Apple has announced that, beginning with macOS 28 (to be released Autumn 2027), Rosetta 2 will be deprecated such that it only supports some older Intel games. My understanding is that Rosetta 2 is essential for running… --- ## [Dub Flag in mkv](https://help.mkvtoolnix.download/t/dub-flag-in-mkv/1587)
**Author:** [@Diabolik](https://help.mkvtoolnix.download/u/Diabolik)\ **Replies:** 2\ **Last updated:** [August 15, 2026, 10:43pm UTC](https://help.mkvtoolnix.download/t/dub-flag-in-mkv/1587 "2026-08-15T22:43:47Z")
Hey! Wondering if you could help me. I’m organizing my library, my final goal is to get rid of all unnecesary tracks in my mkvs and flag them all the same. So i have video (default) - audio (default) - en (noflag) - en (… --- ## [Aspect ratio changed after splitting file into two files](https://help.mkvtoolnix.download/t/aspect-ratio-changed-after-splitting-file-into-two-files/1591)
**Author:** [@nickff](https://help.mkvtoolnix.download/u/nickff)\ **Replies:** 0\ **Last updated:** [August 15, 2026, 12:35am UTC](https://help.mkvtoolnix.download/t/aspect-ratio-changed-after-splitting-file-into-two-files/1591 "2026-08-15T00:35:25Z")
I am trying to split a single MKV file into two separate MKV files. I can successfully split the file into two files, however the aspect ratio of the two new files is different than the original file (it is compressed h… --- ## [Splitting by Chapter Sometimes Compresses Output Display Width?](https://help.mkvtoolnix.download/t/splitting-by-chapter-sometimes-compresses-output-display-width/1590)
**Author:** [@jimmyR1123](https://help.mkvtoolnix.download/u/jimmyR1123)\ **Replies:** 0\ **Last updated:** [August 11, 2026, 12:59am UTC](https://help.mkvtoolnix.download/t/splitting-by-chapter-sometimes-compresses-output-display-width/1590 "2026-08-11T00:59:31Z")
I’m not sure if this is a bug, but I didn’t see anything in forum about it. I have a season of a TV show that is held within a single large MKV file with chapter markers at the start of each episode. When I try to split… --- ## [Unable to see or delete embedded subtitle](https://help.mkvtoolnix.download/t/unable-to-see-or-delete-embedded-subtitle/1588)
**Author:** [@ozmonty](https://help.mkvtoolnix.download/u/ozmonty)\ **Replies:** 2\ **Last updated:** [August 10, 2026, 3:40pm UTC](https://help.mkvtoolnix.download/t/unable-to-see-or-delete-embedded-subtitle/1588 "2026-08-10T15:40:22Z")
When I open the mvk file the embedded subtitle file does not appear I add an srt file and it appears over the original. I am unable to remove original sub. Can anyone help please? [Next page](https://help.mkvtoolnix.download/c/help/4.md?page=1)