Jack connection not working on Musescore 3.6.2 on MacOS 11.6.

• Nov 16, 2021 - 13:58
Reported version
3.5
Type
Functional
Frequency
Few
Severity
S3 - Major
Reproducibility
Always
Status
active
Regression
Yes
Workaround
Yes
Project
MuseScore

Jack server connection not working on Musescore 3.6.2 on MacOS 11.6.

All works perfectly in 2.3.2.

In 3.6.2, no timecode connection to Jack, no audio, playback buttons greyed out.

See https://musescore.org/en/node/324651.

Comments

• Sep 3, 2022 - 09:42
Reported version 3.5 ⇒ 3.6
Workaround No ⇒ Yes

I was put onto the right track by https://musescore.org/en/node/324651.
It looks like that the Musescore app is signed so that only other signed libraries can be loaded into it (but I might be wrong, not an expert). The library Jack provides is unsigned so it won't be loaded. I worked around it by re-signing the Musescore 3.6 app to avoid being so strict, but use the following at your own risk.

  1. Search for Keychain Access in Spotlight an open it.
  2. Click on the menu Keychain Access > Certificate Assistant > Create a Certificate...
  3. Name the certificate Musescore, leave the other fields unchanged, click Create and confirm you want to create a self-signed certificate.
  4. Search for Terminal in Spotlight and open it.
  5. Type: cd /Applications
  6. Type: codesign --force --verbose --sign "Musescore" "MuseScore 3.app"
  7. Close the Terminal window.

Musescore should now be able to connect to Jack when opened.

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