Published: June 30, 2026 · 6 min

You open Maccy and it vanishes from the menu bar before you can blink — or it bounces once in the Dock and dies. The frustration is real, but the root cause nearly always falls into one of three buckets: a corrupt preferences file, a stale build clashing with a newer macOS release, or a damaged history database. The upside: every scenario is repairable in minutes, and most of the time your clipboard history stays intact. Follow these steps from top to bottom. If clipboard entries aren’t being captured rather than crashing, that’s a different issue — see the capture diagnostic guide instead.

The quick answer

Install the newest Maccy build and reboot your Mac. Still crashing? Delete the preferences file (your history is stored separately and won’t be touched). These two actions clear the vast majority of launch failures. Edge cases are covered step by step below.

Step 1 — Install the latest Maccy version

A major macOS upgrade can silently break an older Maccy build. Grab the current release through the built-in updater, run brew upgrade --cask maccy, or download a fresh .dmg and drag it into Applications. If the crash appeared right after a system update, the dedicated guide on Maccy not working after a macOS update covers additional edge cases.

Step 2 — Reboot the Mac

A full restart flushes partially loaded daemons and stale process state that can kill a menu-bar app on launch. It takes thirty seconds and resolves a surprising number of cases on its own.

Step 3 — Reset the preferences file

A corrupted settings file is one of the most common crash triggers, and removing it does not erase your clipboard history — the history database lives in a completely separate location.

1. Quit Maccy completely.
2. In Finder, select Go → Go to Folder and type ~/Library/Preferences.
3. Drag org.p0deje.Maccy.plist to your Desktop as a safety copy.
4. Relaunch Maccy. It opens with factory defaults; if it stays running, the old preferences were the culprit.

Step 4 — Move the database if it’s corrupt

If the crash persists, the history database itself may be damaged. Quit Maccy, navigate to ~/Library/Application Support/Maccy, drag that entire folder to the Desktop, and reopen Maccy. The app generates a fresh database — the old history is gone, but a clean launch confirms the database was at fault. To preserve your data before touching anything, first create a clipboard history backup.

Step 5 — Perform a clean reinstall

Quit Maccy, trash it, download a pristine copy, and install. For a genuinely blank slate, walk through how to completely uninstall Maccy first, then reinstall from scratch.

Step 6 — Rule out login-item conflicts

On rare occasions a third-party keyboard remapper or competing clipboard utility that loads at login can interfere with Maccy’s launch sequence. Temporarily disable other menu-bar apps under System Settings → General → Login Items, then re-enable them one at a time to isolate the offender.

Quick-reference: symptom and fix

Symptom	Likely cause	Fix
Crash right after a macOS update	Outdated build	Update Maccy and reboot
Quits every single launch	Corrupt preferences	Move org.p0deje.Maccy.plist
Crashes even after preferences reset	Damaged database	Move the Maccy folder from Application Support
Nothing helps	Corrupted installation	Clean reinstall
Crashes only at login	Conflict with another app	Review Login Items

If nothing above works

Open the macOS Console app, select Crash Reports in the sidebar, locate the latest Maccy entry, and copy its full text into a new issue on GitHub. That crash log lets the maintainers reproduce the problem far faster. For additional scenarios, consult the full troubleshooting guide or the official documentation.

Preventing future startup crashes

Once Maccy is back on its feet, a handful of habits keep the problem from returning. Most launch failures trace back to stale software or an unchecked, ballooning database — getting ahead of both costs less effort than re-diagnosing later.

• Keep Maccy current. Each new build tracks the latest macOS changes; a periodic brew upgrade --cask maccy is all it takes.
• Verify after major macOS updates. After a big system release, open Maccy and confirm it launches before relying on it in your workflow.
• Back up the history. If your clipboard history doubles as an archive, a routine backup shields you from a corrupt database.
• Shut down cleanly. A hard power-off can leave the database half-written; always quit apps and shut down through the menu.

Frequently asked questions

Why does Maccy crash the instant it opens?

In the vast majority of cases the cause is a corrupt preferences file, an outdated build running on a newer macOS, or a damaged history database. Update Maccy, reboot, then reset the preferences — your history is stored separately and won’t be affected.

Will fixing the crash erase my clipboard history?

Resetting preferences does not touch the history. Only moving or deleting the ~/Library/Application Support/Maccy folder removes it, and that step is a last resort when the database itself is corrupt.

The crash started right after a macOS update — what should I do?

Update Maccy to the latest available build and reboot. Major system releases frequently require a newer Maccy version to function correctly.

Where is Maccy’s preferences file located?

At ~/Library/Preferences/org.p0deje.Maccy.plist. The Library folder is hidden by default; access it via Go → Go to Folder in Finder.

Does reinstalling Maccy automatically clear my settings?

No. A standard reinstall leaves the preferences file and data folder in place. For a truly clean start, manually delete both after uninstalling.