pqrs-org/Karabiner-Elements

Karabiner Elements Driver no longer activates

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#2617 opened on Feb 4, 2021

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bughelp wanted

Description

Like many others here, I am facing the problem of the Karabiner Elements driver not activating on Catalina 10.15.7.

I have tried everything I could find on this forum ... reinstalling multiple versions (12.10, 13.0, 13.3) -- none of it works. No amount of reinstalling, in safe mode or otherwise, makes the "Activate driver" button work. This is what I see:

error

However, opening Preferences shows nothing:

settings

My log fills up with this error:

[2021-02-04 17:52:37.016] [warning] [virtual_hid_device_service] driver_version_ is mismatched: client expected: 10300, actual dext: std::nullopt

Is there a way for me to "allow" the drivers via the command line, so that I can bypass this issue until it's fixed? If so, please share what the command might be. I desperately need my Karabiner back! ;)

Contributor guide

Tech stack
cppshell
Domain
desktop
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
5
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Understanding of macOS driver architectureFamiliarity with kernel extensions (kext/dext)C/C++ debugging skills
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
10
Research direction
Investigate the root cause of the driver activation failure on Catalina 10.15.7. The error log shows a version mismatch between the client (expecting 10300) and the actual dext (std::nullopt). Check if the driver is properly signed and loaded. Look into the Karabiner Elements source code for the virtual hid device service and driver version handling. Search related issues and forum posts for potential solutions or workarounds. Since the issue is over 2 years old with no fix, consult maintainers for the current status or if this is a known limitation.