Quick Look Not Working

Symptom

Pressing Space on a .md or .mkb file in Finder does not show a Markant preview, or shows a generic text preview.

Cause

Quick Look extensions only work in signed builds — the App Store version or TestFlight builds. They do not work in debug/development builds.

Solutions

1. Ensure you have the App Store version

Quick Look extensions are registered when Markant is installed from the Mac App Store. Download it from apps.apple.com.

2. Reset Quick Look

If Quick Look was working and stopped, reset the Quick Look server:

qlmanage -r
qlmanage -r cache

3. Check extension status

Verify the extensions are enabled in System Settings > Privacy & Security > Extensions > Quick Look. Both “MarkantThumbnail” and “MarkantPreview” should be enabled.

4. Restart Finder

Sometimes Finder needs a restart to pick up new Quick Look extensions:

killall Finder

Known limitation

Quick Look extensions cannot work in unsigned debug builds. This is a macOS security restriction, not a Markant bug.